shop manual wb146 5

CEBM016501 BACKHOE LOADER WB146-5 s/n A23001 - UP

OTHERS ELECTRICAL SCHEMATIC

ShopManual

WB146-5

CEBM016501

00-1

BACKHOE LOADER

SERIAL NUMBERSWB146-5A23001and UP

This material is proprietary to Komatsu America Corp. and is not to be reproduced, used, or disclosed except in accordance with written authorization from Komatsu America Corp.

It is our policy to improve our products whenever it is possible and practical to do so. We reserve the right to make changes or add improvements at any time without incurring any obligation to install such changes on products sold previously.

Due to this continuous program of research and development, periodic revisions may be made to this publication. It is recommended that customers contact their distributor for information on the latest revision.

August 2006Copyright 2006 KomatsuPrinted in USADataKom Publishing Division

CONTENTS

01GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01-1

10STRUCTURE, FUNCTION AND MAINTENANCE STANDARD . . . . . . . . . . . . . . . . . . . . 10-1

20TESTING, ADJUSTING AND TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-1

30DISASSEMBLY AND ASSEMBLY. . . . . . . . . . . . . . . . . . . . . . . Will be issued at a later time

90OTHER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90-1

FOREWORD CONTENTS

00-2WB146-5

SAFETY

SAFETY NOTICE

IMPORTANT SAFETY NOTICEProper service and repair is extremely important for the safe operation of your machine. The service and repair techniques recommended and described in this manual are both effective and safe methods of operation. Some of these operations require the use of tools specially designed for the purpose.

To prevent injury to workers, the symbols and are used to mark safety precautions in this manual. The cautions accompanying these symbols should always be followed carefully. If any dangerous situation arises or may possibly arise, first consider safety, and take the necessary actions to deal with the situation.

FOREWORD SAFETY

GENERAL PRECAUTIONS

Mistakes in operation are extremely dangerous. Read the OPERATION & MAINTENANCE MANUAL carefully before operating the machine.

1.Before carrying out any greasing or repairs, read all the precautions given on the decals which are fixed to the machine.

2.When carrying out any operation, always wear safety shoes and helmet. Do not wear loose work clothes, or clothes with buttons missing.

Always wear safety glasses when hitting parts with a hammer. or when grinding parts with a grinder, etc.

3.If welding repairs are needed, always have a trained, ex- perienced welder carry out the work. When carrying out welding work, always wear welding gloves, apron, glasses, cap and other clothes suited for welding work.

4.When carrying out any operation with two or more workers, always agree on the operating procedure before starting. Always inform your fellow workers before starting any step of the operation. Before starting work, hang UNDER REPAIR signs on the controls in the oper- ator's compartment.

5.Keep all tools in good condition and learn the correct way to use them. Decide a place in the repair workshop to keep tools and removed parts. Always keep the tools and parts in their correct places. Always keep the work area clean and make sure that there is no dirt or oil on the floor. Smoke only in the areas provided for smoking. Never smoke while working.

PREPARATIONS FOR WORK

1.Before adding oil or making repairs, park the machine on hard, level ground, and block the wheels or tracks to prevent the machine from moving.

2.Before starting work, lower blade, ripper, bucket or any other work equipment to the ground. If this is not possible, insert the safety pin or use blocks to prevent the work equipment from falling. In addition, be sure to

lock all the control levers and hang warning signs on them.

3.When disassembling or assembling, support the machine with blocks, jacks or stands before starting work.

4.Remove all mud and oil from the steps or other places used to get on and off the machine. Always use the handrails, ladders or steps when getting on or off the machine. Never jump on or off the machine. If it is im- possible to use the handrails, ladders or steps, use a stand to provide safe footing.

PRECAUTIONS DURING WORK

1.When removing the oil filler cap, drain plug or hydraulic pressure measuring plugs, loosen them slowly to prevent the oil from spurting out. Before disconnecting or removing components of the oil, water or air circuits, first remove the pressure completely from the circuit.

2.The water and oil in the circuits are hot when the engine is stopped, so be careful not to get burned. Wait for the oil and water to cool before carrying out any work on the oil or water circuits.

3.Before starting work, remove the leads from the battery.ALWAYS remove the lead from the negative (-) termi- nal first.

4.When raising heavy components, use a hoist or crane.Check that the wire rope, chains and hooks are free from damage. Always use lifting equipment which has ample capacity. Install the lifting equipment at the correct places. Use a hoist or crane and operate slowly to prevent the component from hitting any other part. Do not work with any part still raised by the hoist or crane.

5.When removing covers which are under internal pressure or under pressure from a spring, always leave two bolts in position on opposite sides. Slowly release the pressure, then slowly loosen the bolts to remove.

6.When removing components, be careful not to break or damage the wiring, Damaged wiring may cause electrical fires.

WB146-500-3

7.When removing piping, stop the fuel or oil from spilling out. If any fuel or oil drips on to the floor, wipe it up immediately.Fuel or oil on the floor can cause you to slip, or can even start fires.

8.Gasoline or other fuels should never be used to clean parts. Clean part with appropriate solvents.

9.Be sure to assemble all parts again in their original places. Replace any damaged part with new parts.

When installing hoses and wires, be sure that they will not be damaged by contact with other parts when the machine is being operated.When installing high pressure hoses, make sure that they are not twisted. Damaged tubes are dangerous, so be extremely careful when installing tubes for high pressure circuits. Also check that connecting parts are correctly installed.

10. When assembling or installing parts, always use the specified tightening torques. When installing protective parts such as guards, or parts which vibrate violently or rotate at high speed, be particularly careful to check that they are installed correctly.

11. When aligning two holes, never insert your fingers or hand. Be careful not to get your fingers caught in a hole.

12. When measuring hydraulic pressure, check that the measuring tool is correctly assembled before taking any measure- ments.

13. Take care when removing or installing the tracks of track-type machines. When removing the track, the track separates suddenly, so never let anyone stand at either end of the track.

14. When jump starting the machine, only use a machine of similar size and voltage. Never use a arc welder or other electrical generating equipment to jump start the machine. Carefully review the safety and procedures for jump starting the machine.

00-4WB146-5

GENERAL

This shop manual has been prepared as an aid to improve the quality of repairs by giving the serviceman an accurate understanding of the product and by showing him the correct way to perform repairs and make judgements. Make sure you understand the contents of this manual and use it to full effect at every opportunity.

This shop manual mainly contains the necessary technical information for operations performed in a service workshop. For ease of understanding, the manual is divided into the following sections. These sections are further divided into each main group of components.

GENERAL

This section lists the general machine dimensions, performance specifications, component weights, and fuel, coolant and lubricant specification charts.

STRUCTURE, FUNCTION AND MAINTENANCE STANDARD

This section explains the structure and function of each component. It serves not only to give an understanding of the structure, but also serves as reference material for troubleshooting.TESTING, ADJUSTING AND TROUBLESHOOTING

This section explains checks to be made before and after performing repairs, as well as adjustments to be made at comple- tion of the checks and repairs. Troubleshooting charts correlating Problems to Causes are also included in this section.DISASSEMBLY AND ASSEMBLY

This section explains the order to be followed when removing, installing, disassembling or assembling each component, as well as precautions to be taken for these operations.

NOTICE

The specifications contained in this shop manual are subject to change at any time and without any advance notice. Contact your distributor for the latest information.

FOREWORD GENERAL

WB146-500-5

FOREWORD HOW TO READ THE SHOP MANUAL

00-6WB146-5HOW TO READ THE SHOP MANUAL

VOLUMES

Shop manuals are issued as a guide to carrying out repairs. They are divided as follows:

Chassis volume:Issued for every machine model Engine volume:Issued for each engine series Electrical volume:Each issued as one to cover all models Attachment volume: Each issued as one to cover all modelsThese various volumes are designed to avoid duplication of information. Therefore to deal with all repairs for any model, it is necessary that chassis, engine, electrical and attachment be available.

DISTRIBUTION AND UPDATING

Any additions, amendments or other changes will be sent to your distributors. Get the most up-to-date information before you start any work.

FILING METHOD

1.See the page number on the bottom of the page. File the pages in correct order.

2.Following examples show how to read the page number: Example:10 - 3

Item number (10. Structure and Function) Consecutive page number for each item3.Additional pages: Additional pages are indicated by a hyphen (-) and numbered after the page number. File as in the example.

Example:

REVISED EDITION MARK

When a manual is revised, an edition mark (EFG) is re- corded on the bottom outside corner of the pages.

REVISIONS

Revised pages are shown at the LIST OF REVISED PAGESbetween the title page and SAFETY page.

SYMBOLS

So that the shop manual can be of ample practical use, important places for safety and quality are marked with the following symbols.

SymbolItemRemarksSafetySpecial safety precautions are necessary when performing the work.CautionSpecial technical precautions or other precautions for preserving standards are necessary when performing the work.WeightWeight of parts or systems. Cau- tion necessary when selecting hoisting wire or when working posture is important, etc.TorquePlaces that require special atten- tion for tightening torque during assembly.CoatPlaces to be coated with adhesives and lubricants etc.Oil, waterPlaces where oil, water or fuel must be added, and the capacity.DrainPlaces where oil or water must be drained, and quantity to be drained.10-410-4-1

10-4-2

10-5

Added pages

HOISTING INSTRUCTIONS

HOISTING

WARNING!Heavy parts (25kg or more) must be lifted with a hoist etc. In the DISASSEMBLY AND ASSEMBLY section, every part weighing 25 kg or more is indicated clearly with the symbol.

If a part cannot be smoothly removed from the machine by hoisting, the following checks should be made:

1.Check for removal of all bolts fastening the part to the relative parts.

FOREWORD HOISTING INSTRUCTIONS

WB146-500-72.Check for existence of another part causing interface with the part to be removed.

WIRE ROPES

1.Use adequate ropes depending on the weight of parts to be hoisted, referring to the table below:

Wire ropes, standard Z or S twist ropes without galvanizing

Rope diameterAllowable load

mmkNtons

109.81.0

11.213.71.4

12.515.71.6

1421.62.2

1627.52.8

1835.33.6

2043.14.4

22.454.95.6

3098.110.0

40176.518.0

50274.628.0

60392.240.0

The allowable load value is estimated to be 1/6 or 1/7 of the breaking strength of the rope used.

2.Sling wire ropes from the middle portion of the hook.Slinging near the edge of the hook may cause the rope to slip off the hook during hoisting, and a serious accident can result. Hooks have maximum strength at the middle portion.

3.Do not sling a heavy load with one rope alone, but sling with two or more ropes symmetrically wound on to the load.

WARNING!Slinging with one rope may cause turn- ing of the load during hoisting, untwisting of the rope, or slipping of the rope from its original winding position on the load, which can result in a dangerous accident

4.Do not sling a heavy load with ropes forming a wide hanging angle from the hook. When hoisting a load with two or more ropes, the force subjected to each rope will increase with the hanging angles. The table below shows the variation of allowable load (kg) when hoisting is made with two ropes, each of which is allowed to sling up to 1000 kg vertically, at various hanging angles. When two ropes sling a load vertically, up to 2000 kg of total weight can be suspended. This weight becomes1000 kg when two ropes make a 120 hanging angle. On the other hand, two ropes are subject to an excessive force as large as 4000 kg if they sling a 2000 kg load at a lifting angle of 150

WARNING!Before carrying out the following work, release theresidual pressure from the hydraulic tank. For details, see TESTING AND ADJUSTING, Releasing residual pressure from hydraulic tank.

WARNING!Even if the residual pressure is released from the hydraulic tank, some hydraulic oil flows out when the hose is dis- connected. Accordingly, prepare an oil receiving container.

TYPE 1

DISCONNECTION

1.Release the residual pressure from the hydraulic tank. For details, see TESTING AND ADJUSTING, Releasing residual pressure from hydraulic tank.

2.Hold the adapter (1) and push the hose joint (2) into the mating adapter (3). The adapter can be pushed in about 3.5 mm. Do not hold the rubber cap portion (4).

3.After the hose joint (2) is pushed into the adapter (3), press the rubber cap portion (4) against the adapter until it clicks.

4.Hold the hose adapter (1) or hose (5) and pull it out. Since some hydraulic oil flows out, prepare an oil receiving container.

CONNECTION

1. Hold the hose adapter (1) or hose (5) and insert it in the mating adapter (3), aligning them with each other. Do not hold the rubber cap portion (4).

2.After inserting the hose in the mating adapter, pull it back to check its connecting condition. When the hose is pulled back, the rubber cap portion moves toward the hose about 3.5 mm. This does not indicate an abnormality.

FOREWORD QUICK DISCONNECT COUPLERQUICK DISCONNECT COUPLER

00-10WB146-5straight until sliding prevention ring (1) contacts contact surface aof the hexagonal portion at the male end.

2.Hold in the condition in Step 1, and turn the lever (4) to the right, clockwise.

3.Hold in the condition in Steps 1 and 2, and pull out the whole body(2) to disconnect it.

CONNECTION

1.Hold the mouthpiece of the tightening portion and push body (2) in straight until sliding prevention ring (1) contacts surface a of the hexagonal portion at the male end to connect it.

FOREWORD QUICK DISCONNECT COUPLERTYPE 2DISCONNECTION1.Hold the mouthpiece of the tightening portion and push body (2) in

(2) in straight until sliding prevention ring (1) contacts surface a ofthe hexagonal portion at the male end.

2.Hold in the condition in Step 1, and push until the cover (3) contacts surface a of the hexagonal portion at the male end.

3.Hold in the condition in Steps 1 and 2, and pull out the whole body(2) to disconnect it.

CONNECTION

1.Hold the mouthpiece of the tightening portion and push the body (2) in straight until the slide prevention ring (1) contacts surface a of the hexagonal portion at the male end to connect it.

FOREWORD QUICK DISCONNECT COUPLERTYPE 3DISCONNECTION1.Hold the mouthpiece of the tightening portion and push the body

COATING MATERIALS The recommended coating materials prescribed in the shop manuals are listed below.

CategoryCodePart No.QuantityContainerMain applications, features

AdhesivesLT-1A790-129-9030150 gTube Used to prevent rubber gaskets, rubber cush- ions and cork plugs from coming out

LT-1B

790-129-9050

20 g(2 pes.)

Polyethylene container Used in places requiring an immediately effective, strong adhesive. Used for plastics (except polyethylene, polypropylene, tetrafluoroethylene, and vi- nyl chloride), rubber, metal and non-metal.

LT-209940-0003050 gPolyethylene container Features: Resistance to heat, chemicals Used for anti-loosening and sealant purposes for bolts and plugs.

LT-3790-129-9060 (Set of adhesive and hardening agent)Adh : 1 kg Hardening agent:500 g

Can Used as adhesive or sealant for metal, glass or plastic.

LT-4790-129-9040250 gPolyethylene container Used as sealant for machined holes.

HoltzMH 705790-126-912075 gTube Used as heat-resisting sealant for repairing engine.

3 Bond1735

179-129-9140

2 g

Polyethylene container Quick hardening type adhesive. Cure time: within 5 sec. to 3 min. Used mainly for adhesion of metals, rubbers, plastics and woods.

Aron-al- pha201

790-129-9130

50 g

Polyethylene container Quick hardening type adhesive. Quick cure type (max. strength after 30 min- utes). Used mainly for adhesion of rubbers, plastics and metals.

Loctite648-5079A-129-911050 ccPolyethylene container Features: Resistance to heat, chemicals Used at joint portions subject to high temperature.

Gasket sealantLG-1790-129-9010200 gTube Used as adhesive or sealant for gaskets and packing of power train case, etc.

LG-3

790-129-9070

1 kg

Can Features: Resistance to heat Used as sealant for flange surfaces and bolts at high temperature locations; used to prevent seizure. Used as sealant for heat resistant gasket for at high temperature locations such as engine pre-combustion chamber, exhaust pipe.

FOREWORD COATING MATERIALS

CategoryCodePart No.QuantityContainerMain applications, features

Gasket sealant

LG-4

790-129-9020

200 g

Tube Features: Resistance to water, oil Used as sealant for flange surface, thread.Also possible to use as sealant for flanges with large clearance. Used as sealant for mating surfaces of final drive case, transmission case.

LG-5790-129-90801 kgPolyethylene container Used as sealant for various threads, pipe joints, flanges. for tapered plugs, elbows, nipples of hydraulic piping.

LG-6

09940-00011

250 g

Tube Features: Silicon based, resistant to heat, cold. Used as sealant for flange surface, thread. Used as sealant for oil pan, final drive case, etc.

LG-7

09920-00150

150 g

Tube Features: Silicon based, quick hardening type. Used as sealant for flywheel housing, intake manifold, oil pan, thermostat housing, etc.

3 Bond1211790-129-9090100 gTube Used as heat-resisting sealant for repairing engines.

Molybdenum disulphide lubricantLM-G09940-0005160 gCan Used as lubricant for sliding parts (to prevent squeaking).

LM-P09940-00040200 gTube Used to prevent seizure or scuffing of the thread when press fitting or shrink fitting. Used as lubricant for linkage, bearings, etc.

Grease

G2-LISYG2-400LI SYG2-350LI SYG2-400LI-A SYG2-160LISYGA160CNLI

Various

Various

General purpose type

G2-CASYG2-400CA SYG2-350CA SYG2-400CA-A SYG2-160CASYG2-160CNCA

Various

Various

Used for normal temperature, light load bearing at places in contact with water or steam.

Molybdenum disulphide lubricant

SYG2-400M

400 g (10 per case)

Belows type

Used for places with heavy load.

STANDARD TIGHTENING TORQUE

STANDARD TIGHTENING TORQUE OF BOLTS AND NUTS

The following charts give the standard tightening torques of bolts and nuts. Exceptions are given in DISASSEMBLY AND ASSEMBLY.

Thread diameter of boltWidth across flats

mmmmNmlbf ft

610

13

17

19

2211.8 - 14.7

27 - 34

59 - 74

98 - 123

153 - 1908.70 - 10.84

819.91 - 25.07

1043.51 - 54.57

1272.28 - 90.72

14112.84 - 140.13

1624

27

30

32

36235 - 285

320 - 400

455 - 565

610 - 765

785 - 980173.32 - 210.20

18236.02 - 295.02

20335.59 - 416.72

22449.91 - 564.23

24578.98 - 722.81

2741

46

50

55

601150 - 1440

1520 - 1910

1960 - 2450

2450 - 3040

2890 - 3630848.19 - 1062.09

301121.09 - 1408.74

331445.62 - 1807.02

361807.02 - 2242.19

392131.55 - 2677.35

Thread diameter of bolt

Width across flats

mmmmNmlbf ft

6105.9 - 9.84.35 - 7.22

81313.7 - 23.510.10 - 17.33

101434.3 - 46.125.29 - 34.00

122774.5 - 90.254.94 - 66.52

FOREWORD STANDARD TIGHTENING TORQUE

TIGHTENING TORQUE OF HOSE NUTS

Use these torques for hose nuts.

Nominal No.Thread diameterWidth across flatTightening torque

mmmmNmlbf ft

02141919.6 - 29.414.5 - 21.7

03182429.4 - 68.621.7 - 50.6

04222758.9 - 98.144.4 - 72.4

052432107.9 - 166.779.6 - 123.0

063036147.1 - 205.9108.5 - 151.9

103341147.1 - 245.1108.5 - 180.8

123646196.2 - 294.2144.7 - 217.0

144255245.2 - 343.2180.9 - 253.1

TIGHTENING TORQUE OF SPLIT FLANGE BOLTS

Use these torques for split flange bolts.

Thread diameterWidth across flatTightening torque

mmmmNmkgm

101459 - 7443.51 - 54.57

121798 - 12372.28 - 90.72

1622235 - 285173.32 - 210.20

TIGHTENING TORQUE FOR FLARED NUTS

Use these torques for flared part of nut.

Thread diameterWidth across flatTightening torque

mmmmNmlbf ft

141924.5 4.918.0 3.6

182449 19.636.1 14.4

222778.5 19.657.8 14.4

2432137.3 29.4101.2 21.6

3036176.5 29.4130.1 21.6

3341196.1 49144.6 36.1

3646245.2 49180.8 36.1

4255294.2 49216.9 36.1


TABLE OF TIGHTENING TORQUES FOR O-RING BOSS PIPING JOINTS

Unless there are special instructions, tighten the O-ring boss piping joints to the torque below.

Norminal No.Thread diameterWidth across flatTightening torque - Nm (lbf ft)

mmmmRangeTarget

0214

Varies depending on type of connector.35 - 63 (25.81 - 46.46)44 (32.45))

03, 042084 - 132 (61.95 - 97.35)103 (75.96)

05, 0624128 - 186 (94.40 - 137.18)157 (115.79)

10, 1233363 - 480 (267.73 - 354.02)422 (311.25)

1442746 - 1010 (550.22 - 744.93)883 (651.26)

TABLE OF TIGHTENING TORQUES FOR O-RING BOSS PLUGS

Unless there are special instructions, tighten the O-ring boss plugs to the torque below.

Norminal No.Thread diameterWidth across flatTightening torque - Nm (lbf lb)

mmmmRangeTarget

0808145.88 - 8.82 (4.33 - 6.50)7.35 (5.42)

1010179.8 - 12.74 (7.22 - 9.39)11.27 (8.31)

12121914.7 - 19.6 (10.84 - 14.45)17.64 (13.01)

14142219.6 - 24.5 (14.45 - 18.07)22.54 (16.62)

16162424.5 - 34.3 (18.07 - 25.29)29.4 (21.68)

18182734.3 - 44.1 (25.29 - 32.52)39.2 (28.91)

20203044.1 - 53.9 (32.52 - 39.75)49.0 (36.14)

24243258.8 - 78.4 (43.36 - 57.82)68.6 (50.59)

30303293.1 - 122.5 (68.66 - 90.35)107.8 (79.50)

3333_107.8 - 147.0 (79.50 - 108.42)124.4 (91.75)

363636127.4 - 176.4 (93.96 - 130.10)151.9 (112.03)

4242_181.3 - 240.1 (133.72 - 177.08)210.7 (155.40)

5252_274.4 - 367.5 (202.38 - 271.05)323.4 (238.52)

TIGHTENING TORQUE TABLE FOR HOSES (TAPER SEAL TYPE AND FACE SEAL TYPE)

Tighten the hoses (taper seal type and face seal type) to the following torque, unless otherwise specified. Apply the following torque when the threads are coated (wet) with engine oil.

Nominal hose sizeWidth across flatsTightening torque - Nm (lbf ft)Taper sealFace seal

RangeTargetThread size(mm)Nominal threadsize - TPIRoot diameter (mm)(Reference)

021934 - 54 (25.0 - 39.8)44 (32.4)-9/16 - 18UN14.3

34 - 63 (25.0 - 46.4)44 (32.4)14--

032254 - 93 (39.8 - 68.5)74 (54.5)-11/16 -16UN17.5

2459 - 98 (43.5 - 72.2)78 (57.5)18--

042784 - 132 (61.9 - 97.3)103 (75.9)2213/16 - 16UN20.6

0532128 - 186 (94.4 - 137.1)157 (115.7)241 - 14UNS25.4

0636177 - 245 (130.5 - 180.7)216 (159.3)301 3/16 - 12UN30.2

(10)41177 - 245 (130.5 - 180.7)216 (159.3)33--

(12)46197 - 294 (145.3 - 216.8)245 (180.7)36--

(14)55246 - 343 (181.4 - 252.9)294 (216.8)42--


ELECTRIC WIRE CODE

In the wiring diagrams, various colors and symbols are employed to indicate the thickness of wires. This wire code table will help you understand WIRING DIAGRAMS.

Example:05WB indicates a cable having a nominal number 05 and white coating with black stripe.

CLASSIFICATION BY THICKNESS

Nominal numberCopper wireCable O.D. (mm)Current rating (A)

Applicable circuit

Number of strandsDia. Of strand (mm)Cross section(mm)

0.85110.320.882.412Starting, lighting, signal etc.

2260.322.093.120Lighting, signal etc.

5650.325.234.637Charging and signal

15840.4513.367.059Starting (Glow plug)

40850.8042.7311.4135Starting

601270.8063.8413.6178Starting

1002170.80109.117.6230Starting

CLASSIFICATION BY COLOR AND CODE

PriorityCircuitsClassificationChargingGroundStartingLightingInstrumentSignalOther

1PrimaryCodeWBBRYGL

ColorWhiteBlackBlackRedYellowGreenBlue

2AuxiliaryCodeWRBWRWYRGWLW

ColorWhite & RedBlack & WhiteRed & WhiteYellow & RedGreen & WhiteBlue & White

3CodeWBBYRBYBGRLR

ColorWhite & BlackBlack & Yel- lowRed & BlackYellow & BlackGreen & RedBlue & Red

4CodeWLBRRYYGGYLY

ColorWhite & BlueBlack & RedRed & Yel- lowYellow & GreenGreen & YellowBlue & Yel- low

5CodeWGRGYLGBLB

ColorWhite & GreenRed & GreenYellow & BlueGreen & BlackBlue & Black

6CodeRLYWGL

ColorRed & BlueYellow & WhiteGreen & Blue

FOREWORD ELECTRIC WIRE CODE

CONVERSION TABLES

METHOD OF USING THE CONVERSION TABLE

The Conversion Table in this section is provided to enable simple conversion of figures. For details of the method of using theConversion Table, see the example given below. EXAMPLEMethod of using the Conversion Table to convert from millimeters to inches.

1.Convert 55 mm into inches.

A. Locate the number 50 in the vertical column at the left side, take this as E, then draw a horizontal line from E. B. Locate the number 5 in the row across the top, take this as F, then draw a perpendicular line down from F.C. Take the point where the two lines cross as G. This point G gives the value when converting from millimeters to inches. Therefore, 55 millimeters = 2.165 inches.

2.Convert 550 mm into inches.

A. The number 550 does not appear in the table, so divide by 10 (move the decimal one place to the left) to convert it to55 mm.

B. Carry out the same procedure as above to convert 55 mm to 2.165 inches.

C. The original value (550 mm) was divided by 10, so multiply 2.165 inches by 10 (move the decimal one place to the right) to return to the original value. This gives 550 mm = 21.65 inches.

F

Millimeters to inches1 mm = 0.03937 in

012345678901020304000.3940.7871.1811.5750.0390.4330.8271.2201.6140.0790.4720.8661.2601.6540.1180.5120.9061.2991.6930.1570.5510.9451.3391.7320.1970.5910.9841.3781.772G0.2360.6301.0241.4171.8112.2052.5982.9923.3863.7800.2760.6691.0631.4571.8502.2442.6383.0323.4253.8190.3150.7091.1021.4961.8902.2832.6773.0713.4653.8580.3540.7481.1421.5361.9292.3232.7173.1103.5043.89850607080901.9692.3622.7563.1503.5432.0082.4022.7953.1893.5832.0472.4412.8353.2283.6222.0872.4802.8743.2683.6612.1262.5202.9133.3073.7012.1652.5592.9533.3463.740E

FOREWORD CONVERSION TABLES

Millimeters to Inches1 mm = 0.03937 in

0123456789

0

10

20

30

40

50

60

70

80

900

0.394

0.787

1.181

1.575

1.969

2.362

2.756

3.150

3.5430.039

0.433

0.827

1.220

1.614

2.008

2.402

2.795

3.189

3.5830.079

0.472

0.866

1.260

1.654

2.047

2.441

2.835

3.228

3.6220.118

0.512

0.906

1.299

1.693

2.087

2.480

2.874

3.268

3.6610.157

0.551

0.945

1.339

1.732

2.126

2.520

2.913

3.307

3.7010.197

0.591

0.984

1.378

1.772

2.165

2.559

2.953

3.346

3.7400.236

0.630

1.024

1.417

1.811

2.205

2.598

2.992

3.386

3.7800.276

0.669

1.063

1.457

1.850

2.244

2.638

3.032

3.425

3.8190.315

0.709

1.102

1.496

1.890

2.283

2.677

3.071

3.465

3.8580.354

0.748

1.142

1.536

1.929

2.323

2.717

3.110

3.504

3.898

Kilogram to Pound1 kg = 2.2046 lb

0123456789

0

10

20

30

40

50

60

70

80

900

22.05

44.09

66.14

88.18

110.23

132.28

154.32

176.37

198.422.20

24.25

46.30

68.34

90.39

112.44

134.48

156.53

178.57

200.624.41

26.46

48.50

70.55

92.59

114.64

136.69

158.73

180.78

202.836.61

28.66

50.71

72.75

94.80

116.85

138.89

160.94

182.98

205.038.82

30.86

51.91

74.96

97.00

119.05

141.10

163.14

185.19

207.2411.02

33.07

55.12

77.16

99.21

121.25

143.30

165.35

187.39

209.4413.23

35.27

57.32

79.37

101.41

123.46

145.51

167.55

189.60

211.6415.43

37.48

59.53

81.57

103.62

125.66

147.71

169.76

191.80

213.8517.64

39.68

61.73

83.78

105.82

127.87

149.91

171.96

194.01

216.0519.84

41.89

63.93

85.98

108.03

130.07

152.12

174.17

196.21

218.26

Liter to U.S. Gallon1 L = 0.2642 U.S. Gal

0123456789

0

10

20

30

40

50

60

70

80

900

2.642

5.283

7.925

10.567

13.209

15.850

18.492

21.134

23.7750.264

2.906

5.548

8.189

10.831

13.473

16.115

18.756

21.398

24.0400.528

3.170

5.812

8.454

11.095

13.737

16.379

19.020

21.662

24.3040.793

3.434

6.076

8.718

11.359

14.001

16.643

19.285

21.926

24.5681.057

3.698

6.340

8.982

11.624

14.265

16.907

19.549

22.190

24.8321.321

3.963

6.604

9.246

11.888

14.529

17.171

19.813

22.455

25.0961.585

4.227

6.869

9.510

12.152

14.795

17.435

20.077

22.719

25.3611.849

4.491

7.133

9.774

12.416

15.058

17.700

20.341

22.983

25.6252.113

4.755

7.397

10.039

12.680

15.322

17.964

20.605

23.247

25.8892.378

5.019

7.661

10.303

12.944

15.586

18.228

20.870

23.511

26.153

Liter to U.K. Gallon1 L = 0.21997 U.K. Gal

0123456789

0

10

20

30

40

50

60

70

80

900

2.200

4.399

6.599

8.799

10.998

13.198

15.398

17.598

19.7970.220

2.420

4.619

6.819

9.019

11.281

13.418

15.618

17.818

20.0170.440

2.640

4.839

7.039

9.239

11.438

13.638

15.838

18.037

20.2370.660

2.860

5.059

7.259

9.459

11.658

13.858

16.058

18.257

20.4570.880

3.080

5.279

7.479

9.679

11.878

14.078

16.278

18.477

20.6771.100

3.300

5.499

7.699

9.899

12.098

14.298

16.498

18.697

20.8971.320

3.520

5.719

7.919

10.119

12.318

14.518

16.718

18.917

21.1171.540

3.740

5.939

8.139

10.339

12.528

14.738

16.938

19.137

21.3371.760

3.950

6.159

8.359

10.559

12.758

14.958

17.158

19.357

21.5571.980

4.179

6.379

8.579

10.778

12.978

15.178

17.378

19.577

21.777

WB146-500-19

Nm to lbf. ft.1 Nm = 0.737 lbf. ft.

0123456789

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

1900

7.37

14.74

22.11

29.48

36.85

44.22

51.59

58.96

66.33

73.7

81.07

88.44

95.81

103.18

110.55

117.92

125.29

132.66

140.030.737

8.107

15.477

22.847

30.217

37.587

44.957

52.327

59.697

67.067

74.437

81.807

89.177

96.547

103.917

111.287

118.657

126.027

133.397

140.7671.474

8.884

16.214

23.584

30.954

38.324

45.694

53.064

60.434

67.804

75.174

82.544

89.914

97.284

104.654

112.024

119.394

126.764

134.134

141.5042.211

9.581

16.951

24.321

31.691

39.061

46.431

53.801

61.171

68.541

75.911

83.281

90.651

98.021

105.391

112.761

120.131

127.501

134.871

142.2412.948

10.318

17.688

25.058

32.428

39.798

47.168

54.538

61.908

69.278

76.648

84.018

91.388

98.758

106.128

113.498

120.868

128.238

135.608

142.9783.685

11.055

18.425

25.795

33.165

40.535

47.905

55.275

62.645

70.015

77.385

84.755

92.125

99.495

106.865

114.235

121.605

128.975

136.345

143.7154.422

11.792

19.126

26.532

33.902

41.272

48.642

56.012

63.382

70.752

78.122

85.492

92.862

100.232

107.602

114.972

122.342

129.712

137.082

144.4525.159

12.259

19.899

27.269

34.639

42.009

49.379

56.749

64.119

71.489

78.859

86.229

93.599

100.969

108.339

115.709

123.079

130.449

137.819

145.1895.896

13.266

20.636

28.006

35.376

42.746

50.116

57.486

64.856

72.226

79.596

86.966

94.336

101.706

109.076

116.446

123.816

131.186

138.556

145.9266.63

14.003

21.373

28.743

36.113

43.483

50.853

58.223

65.593

72.963

80.333

87.703

95.073

102.443

109.813

117.183

124.553

131.923

139.293

146.663

00-20WB146-5

Nm to lbf. inf1 Nm = 8.85 lbf. inf

0123456789

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

1900

88.5

177

265.5

354

442.5

531

619.5

708

796.5

885

973.5

1062

1150.5

1239

1327.5

1416

1504.5

1593

1681.58.85

97.35

185.85

274.35

362.85

451.35

539.85

628.35

716.85

805.35

893.85

982.35

1070.85

1159.35

1247.85

1336.35

1424.85

1513.35

1601.85

1690.3517.7

106.2

194.7

283.2

371.7

460.2

548.7

637.2

725.7

814.2

902.7

991.2

1079.7

1168.2

1256.7

1345.2

1433.7

1522.2

1610.7

1699.226.55

115.05

203.55

292.05

380.55

469.05

557.55

646.05

734.55

823.05

911.55

1000.05

1088.55

1177.05

1265.55

1354.05

1442.55

1531.05

1619.55

1708.0535.4

123.9

212.4

300.9

389.4

477.9

566.4

654.9

743.4

831.9

920.4

1008.9

1097.4

1185.9

1274.4

1362.9

1451.4

1539.9

1628.4

1716.944.25

132.75

221.25

309.75

398.25

486.75

575.25

663.75

752.25

840.75

929.25

1017.75

1106.25

1194.75

1283.25

1371.75

1460.25

1548.75

1637.25

1725.7553.1

141.6

230.1

318.6

407.1

495.6

584.1

672.6

761.1

849.6

938.1

1026.6

1115.1

1203.6

1292.1

1380.6

1469.1

1557.6

1646.1

1734.661.95

150.45

238.95

327.45

415.95

504.45

592.95

681.45

769.95

858.45

946.95

1035.45

1123.95

1212.45

1300.95

1389.45

1477.95

1566.45

1654.95

1743.4570.8

159.3

247.8

336.3

424.8

513.3

601.8

690.3

778.8

867.3

955.8

1044.3

1132.8

1221.3

1309.8

1398.3

1486.8

1575.3

1663.8

1752.379.65

168.15

256.65

345.15

433.65

522.15

610.65

699.15

787.65

876.15

964.65

1053.15

1141.65

1230.15

1318.65

1407.15

1495.65

1584.15

1672.65

1761.15

WB146-500-21

Temperature

Fahrenheit Centigrade Conversion; a simple way to convert a Fahrenheit temperature reading into a Centigrade temperature reading or vise versa is to enter the accompanying table in the center or boldface column of figures. These figures refer to the temperature in either Fahrenheit or Centigrade degrees. If it is desired to convert from Fahrenheit to Centigrade degrees, consider the center column as a table of Fahrenheit temperatures and read the corresponding Centigrade temperature in the column at the left. If it is desired to convert from Centigrade to Fahrenheit degrees, consider the center column as a table of Centigrade values, and read the corresponding Fahrenheit temperature on the right.

CFCFCFCF

-40.4-37.2-34.4-31.7-28.9

-28.3-27.8-27.2-26.7-26.1

-25.6-25.0-24.4-23.9-23.3

-22.8-22.2-21.7-21.1-20.6

-20.0-19.4-18.9-18.3-17.8

-17.2-16.7-16.1-15.6-15.0

-14.4-13.9-13.3-12.8-12.2-40-35-30-25-20

-19-18-17-16-15

-14-13-12-11-10

-9-8-7-6-5

-4-3-2-10

12345

678910-40.0-31.0-22.0-13.0-4.0

-2.2-0.41.43.25.0

6.88.610.412.214.0

15.817.619.421.223.0

24.826.628.430.232.0

33.835.637.439.241.0

42.844.646.448.250.0-11.7-11.1-10.6-10.0-9.4

-8.9-8.3-7.8-7.2-6.7

-6.1-5.6-5.0-4.4-3.9

-3.3-2.8-2.2-1.7-1.1

-0.600.61.11.7

2.22.83.33.94.4

5.05.66.16.77.21112131415

1617181920

2122232425

2627282930

3132333435

3637383940

414243444551.853.655.457.259.0

60.862.664.466.268.0

69.871.673.475.277.0

78.880.682.484.286.0

87.889.691.493.295.0

96.898.6100.4102.2104.0

105.8107.6109.4111.2113.07.88.38.99.410.0

10.611.111.712.212.8

13.313.914.415.015.6

16.116.717.217.818.3

18.919.420.020.621.1

21.722.222.823.323.9

24.425.025.626.126.74647484950

5152535455

5657585960

6162636465

6667686970

7172737475

7677787980114.8116.6118.4120.2122.0

123.8125.6127.4129.2131.0

132.8134.6136.4138.2140.0

141.8143.6145.4147.2149.0

150.8152.6154.4156.2158.0

159.8161.6163.4165.2167.0

168.8170.6172.4174.2176.027.227.828.328.929.4

30.030.631.131.732.2

32.833.333.934.435.0

35.636.136.737.237.8

40.643.346.148.951.7

54.457.260.062.765.6

68.371.173.976.779.48182838485

8687888990

9192939495

96979899100

105110115120125

130135140145150

155160165170175117.8179.6181.4183.2185.0

186.8188.6190.4192.2194.0

195.8197.6199.4201.2203.0

204.8206.6208.4210.2212.0

221.0230.0239.0248.0257.0

266.0275.0284.0293.0302.0

311.0320.0329.0338.0347.0

00-22WB146-5

01GENERAL

SPECIFICATIONS ................................................................................................................................................................ 01-2WEIGHT TABLE .................................................................................................................................................................. 01-3FUEL COOLANT AND LUBRICANTS .............................................................................................................................. 01-4

WB146-501-1

GENERALSPECIFICATIONS

SPECIFICATIONS

ITEMUNITWB146-5 A23001 and UP

01-2WB146-5

Operating weight

MinimumkgMaximum

Loader

GP w/BOCE

0.95

MP w/BOCE0.99

305 mm Edge0.07

Bucket capacity

457 mm Edgem

0.12

Backhoe

609 mm Edge0.18

762 mm Edge0.23

915 mm Edge0.29

ModelS4D102LE-2

Diesel engine

Max powerkW69

Max torqueNm407

AlternatorV12

OutputA95

Electrical system

Ground---NEG BatteryAh @ V 100StarterkW3.2

Forward 1st

6.3

Forward 2nd11.4

Forward 3rd21.3

Travel speeds

Forward 4th37.8 km/hReverse 1st6.3

Reverse 2nd11.4

Reverse 3rd21.3

Reverse 4th37.8

Front tire pressure

Front

kg/cm

3.26 - 3.36

Rear1.83 - 1.93

GENERALWEIGHT TABLE

WB146-501-3WEIGHT TABLE This table is a guide for use when transporting or handling components.

Unit: kg

ComponentWB146-5 A23001 and UP

FUEL COOLANT AND LUBRICANTS

It is not our policy to approve fuel, coolant and lubricants or to guarantee performance in service. The responsibility for the quality of the fuel, coolant and lubricant must remain with the supplier.

When in doubt, consult your Komatsu distributor. The following table shows specified fuel, coolant and lubricants recommended for this machine.

GENERALFUEL COOLANT AND LUBRICANTS

01-4WB146-5

ReservoirKind of fluid

Ambient Temperature - CCapacity

-30-20-1001020304050SpecifiedRefill

SAE 5W-30

SAE 10W

Engine oil pan

SAE 20W-20

SAE 30

SAE 40

11 L13 L

Oil API CI-4SAE 10W-30

SAE 15W-40

SAE 5W*

Hydraulic system

SAE 10W

SAE 30

150 L92 L

SAE 10W-30+

HEES150 L92 L

Front axle diff

Final gear

See Note 1

6.5 L6.5 L

1 L each1 L each

Oil API CI-4Rear axle diff14.5 L14.5 L

Final gear1.5 L each1.5 L each

Transmission

ATFGM DEXRON II D

20 L17 L

Brakes0.8 L0.8 L

Fuel tankDiesel fuel

ASTMD975 No. 1130 L-ASTM D975 No. 2

Engine cool-ing systemCoolantAF-NAC14 L-

OPTION FOR VERY COLD AREAS:If the temperature is below 10C, contact your distributor for advise on the type of oil to be used.

Note 1:

For axle oil, use only the recommended oil as follows.

SHELL ..................................................................DONAX TD

CALTEX ...............................................................RPM TRACTOR HYDRAULIC FLUID CHEVRON ...........................................................TRACTOR HYDRAULIC FLUID TEXACO ..............................................................TEXTRAN TDH OIL MOBIL..................................................................MOBILFLUID 422 or 424

API ................................ American Petroleum Institute ASTM............................ American Society of Testing and Materials NLGI ............................. National Lubricating Grease InstituteSAE ............................... Society of Automotive Engineers

Specified Capacity ........ Total amount of oil including oil for components and piping.

Refill Capacity .............. Amount of oil needed to refill system during normal maintenance.

Other equipment may be necessary when operating the machine at temperatures below -20C. Consult your Komatsu distributor for your specific needs.

NOTE Use only diesel fuel. The engine mounted in this machine employs electronic control and a high pressure fuel injection device to obtain good fuel consumption and good exhaust characteristics. For this reason, it requires high precision for the parts and good lubrication. If kerosene or other fuel with low lubricating ability is used, there will be a significant drop in durability.

WB146-501-5

GENERAL

MEMORANDA

01-6WB146-5

10STRUCTURE, FUNCTION AND MAINTENANCE STANDARD

POWER TRAIN ...................................................................................................................................................... 10-3DESCRIPTION..................................................................................................................................................... 10-3POWER FLOW .................................................................................................................................................... 10-3TRANSMISSION DIAGRAM ................................................................................................................................ 10-5TRANSMISSION .................................................................................................................................................... 10-7COMPLETE ASSEMBLY ................................................................................................................................... 10-7FORWARD REVERSE CLUTCH ..................................................................................................................... 10-111ST THROUGH 4TH SPEED SHAFT .............................................................................................................. 10-114WD SHAFT ...................................................................................................................................................... 10-12FRONT AXLE....................................................................................................................................................... 10-13COMPLETE ASSEMBLY ................................................................................................................................. 10-13REAR AXLE ......................................................................................................................................................... 10-16COMPLETE ASSEMBLY ................................................................................................................................. 10-16DIFFERENTIAL ................................................................................................................................................ 10-17PLANETARY ..................................................................................................................................................... 10-18WORK BRAKES................................................................................................................................................ 10-19DIFFERENTIAL LOCK .................................................................................................................................... 10-20HYDRAULIC PUMP ............................................................................................................................................ 10-21MAIN PUMP ...................................................................................................................................................... 10-22DELIVERY CONTROL VALVE ...................................................................................................................... 10-26MAIN CONTROL VALVE .................................................................................................................................. 10-32CLSS ...................................................................................................................................................................... 10-39DESCRIPTION................................................................................................................................................... 10-39OPERATING PRINCIPLES .............................................................................................................................. 10-40STEERING UNIT.................................................................................................................................................. 10-55TECHNICAL DATA .......................................................................................................................................... 10-55OPERATION ...................................................................................................................................................... 10-55PPC VALVE .......................................................................................................................................................... 10-56LOADER ............................................................................................................................................................ 10-56OUTRIGGER ..................................................................................................................................................... 10-61BACKHOE ......................................................................................................................................................... 10-65SOLENOID VALVE ............................................................................................................................................. 10-67HYDRAULIC CONTROLS W/O MP BUCKET .............................................................................................. 10-67HYDRAULIC CONTROLS WITH MP BUCKET............................................................................................ 10-68LOADER CYLINDERS ........................................................................................................................................ 10-69BOOM................................................................................................................................................................. 10-69BUCKET............................................................................................................................................................. 10-70MP BUCKET ...................................................................................................................................................... 10-71

WB146-510-1

BACKHOE CYLINDERS..................................................................................................................................... 10-72BOOM................................................................................................................................................................. 10-72ARM ................................................................................................................................................................... 10-73BUCKET............................................................................................................................................................. 10-74TELESCOPIC ARM CYLINDER ..................................................................................................................... 10-75SWING ............................................................................................................................................................... 10-76OUTRIGGER ..................................................................................................................................................... 10-77WORK EQUIPMENT ........................................................................................................................................... 10-78LOADER ............................................................................................................................................................ 10-78BACKHOE ......................................................................................................................................................... 10-80AIR CONDITIONING .......................................................................................................................................... 10-83

STRUCTURE, FUNCTION ANDMAINTENANCE STANDARDTABLE OF CONTENTS

10-2WB146-5

POWER TRAIN

B

Engine

F

Front Axle

CTorque ConverterGRear Axle

DTransmissionHFront Drive Shaft

EHydraulic PumpIRear Drive Shaft

DESCRIPTION

The driving power for the engine b is transmitted through the flywheel to the converter c. The converter uses hydraulic oil to convert the torque transmitted by the engine into driving power. The converter transmits motion to the drive shaft of the transmission d and to the drive shaft of the hydraulic pump e.

The transmission d has two hydraulically activated clutches that can be selected by an electrically controlled gear selector.The same switch also controls the four speed clutch packs.

The driving power is transmitted from the transmission flanges to the front f and rear g axles through the drive shafts h and i. The driving power transmitted to the front f and rear g axles is reduced by the differentials and then transmitted to the planetary gear through the differential shafts.

POWER FLOW

Front Axle

GearTransmissionDifferentialPlanetTotal

1st5.533

2.462

681.722

2nd3.3649.627

3rd1.53222.627

4th0.8111.963

Rear Axle

GearTransmissionDifferentialPlanetTotal

1st5.533

2.75

6.497.338

2nd3.3659.136

3rd1.53226.963

4th0.8114.256

STRUCTURE, FUNCTION ANDMAINTENANCE STANDARDPOWER TRAIN

WB146-510-3

b Engine

F Front Axle

j Rear Tires

c ConvertG Rear Axle1) Front Tires

d TransmissionH Front Drive Shaft

e Hydraulic PumpI Rear Drive Shaft

10-4WB146-5

TRANSMISSION DIAGRAM

b Engine

E Transmission

H Rear Axle Flange

c Torque ConverterF Reverse ClutchI 4WD Clutch

d Forward ClutchG Hydraulic PumpJ Front Axle Flange

STRUCTURE, FUNCTION ANDMAINTENANCE STANDARDTRANSMISSION DIAGRAM

WB146-510-5

B Converter Valve

G

Reverse Clutch

1!

Control Valve

C ConverterHMax Pressure Valve1@Check Valve

D EngineISpin On Filter1#Check Valve

E Oil CoolerJPump1$4WD Solenoid

F Forward Clutch1)Suction Strainer1%4WD Clutch

10-6WB146-5

TRANSMISSION

COMPLETE ASSEMBLY

B Shift Lever

F Suction Strainer

J

4WD Solenoid

C Torque ConverterD Spin On FilterG 4th Gear SensorH Reverse SolenoidabFrom Oil CoolerTo Oil Cooler

E Oil Temperature SenderI Forward Solenoid

STRUCTURE, FUNCTION ANDMAINTENANCE STANDARDTRANSMISSION

WB146-510-7

B Pump Drive ShaftH Rear Axle Flange1# 4WD Clutch

C Forward Reverse ShaftI 3rd Driven Gear1$ 4WD Clutch Shaft

D Reverse Gear ClutchJ 4th Driven Gear1% Front Axle Flange

E Forward Gear Clutch1) 4WD Drive Gear1^ 2nd Driven Gear

F Reverse Idler Gear Shaft1! 1st Driven Gear1& Rear Output Shaft

G Drive Gears and Shaft1@ 4WD Driven Gear1* Torque Converter

10-8WB146-5

B Gear Shift Lever

H 3rd & 4th Selecting Rod

1# Spin On Filter

C Centering SpringI 1st &2nd Selecting Fork1$ Cold Oil Relief Valve

D Return SpringJ 4th Selecting Sensor1% Return Spring

E Check Ball1) 3rd & 4th Selector1^ Return Spring

F 3rd & 4th Selecting Fork1! 1st & 2nd Selector1& Return Spring

G 1st & 2nd Selecting Rod1@ Suction Strainer

WB146-510-9

B Forward Reverse Solenoid

H Valve

1# Spool

C 4WD SolenoidI Return Spring1$ Forward Solenoid

D PistonJ Valve1% Reverse Solenoid

E Return Spring1) Rod1^ Check Ball

F Return Spring1! Return Spring1& Return Spring

G Spring Guide Pin1@ Spool Return Spring

10-10WB146-5

FORWARD REVERSE CLUTCH

B Reverse Gear

E Reverse Clutch Pistona

Reverse Clutch Port

C Forward GearF Thrust RingbForward Clutch Port

D Forward Clutch PistonG ShaftcLubrication Port

1ST THROUGH 4TH SPEED SHAFT

B 2nd Driver GearE 4th Driven GearH Thrust Ring

C 1st Driven GearF 3rd Driven GearI Synchronizer

D 4WD Gearg Rear Output Shaft

WB146-510-11

4WD SHAFT

B Front Output ShaftE Cylindera4WD Pressure Port

C 4WD Driven GearF Spring

D Thrust RingG Disc

10-12WB146-5

FRONT AXLE

COMPLETE ASSEMBLY

STRUCTURE, FUNCTION ANDMAINTENANCE STANDARDFRONT AXLE

WB146-510-13B Steering CylinderE Tie Rod Nuth Mounting Pin BushingC Oil Refill PlugF Adjustment Screwa Left Cylinder PortD Oil Drain PlugG Lock Nutb Right Cylinder Port

Check ItemCriteriaRemedyStandardSizeToleranceStandardClearanceClearanceLimitShaftBushingiPin and Bushing Clearance5050050.19+0.04------ReplaceUnit:mm

-0.0390

DIFFERENTIAL

B Side Gear

F Adjustment Lock Nut

J Bearing Spacer

1# Bearing Lock Nut

C Ring GearG Axle Shaft1) Outboard Bearing1$ Inboard Bearing

D Dowel PinH Dowel Pin1! Lip Seal Ring1% Pinion Gear

E Driven GearI Differential Housing1@ Lip Seal Ring Cover1^ Oil Drain Plug

Unit : mm

Check ItemCriteriaRemedy

Standard ClearanceClearance Limit

1&Axle Clearance------

Adjust

1*Ring and Pinion Gear Backlash0.18 to 0.280.28

1(Pinion Preload - w/o lip seal92 to 137 Nm

2)Ring and Pinion Gear Preload - w/o lip seal129.5 to 194.5 Nm

10-14WB146-5

PLANETARY

WB146-510-15B Planetary CarrierJ Belleville Washer1& Lip Ring SealC Planetary Gear1) Upper King Pin Bushing1* Tapered Roller BearingD Ring Gear1! Lip Ring Seal1( Retaining RingE Carrier Gear1@ Axle Housing2) Bolt BushingF Wheel Hub1# Spherical Bearing2! Stud BoltG Lip Ring Seal1$ Lower King Pin Bushing2@ Oil Drain PlugH Upper King Pin1% Lower King PinI Adjustment Shim1^ Belleville Washer

Unit:mm

2#Hub Rotation Torque---Adjust

2$Axle Shaft Clearance---

REAR AXLE

COMPLETE ASSEMBLY

B Input FlangeC Differential PortionF Planetary PortionG Parking Brake LeversJ Oil Drain Plug1) Axle Housing Breather

D Brake PortionE Axle HousingH Brake Bleeder ScrewsI Oil Fill And Level Plugsa Brake Port .......................40.8 kg/cmb Diff Lock Port............. 1295.4 kg/cm

STRUCTURE, FUNCTION ANDMAINTENANCE STANDARDREAR AXLE

10-16WB146-5

DIFFERENTIAL

B Tapered Roller BearingF Differential HousingJ Bearing Lock Nut1# Pinion Gear

C Side GearG Bearing Lock Nut1) Lip Oil Seal1$ Differential Housing

D Rotating GearH Axle Shaft1! Input Flange

E Ring GearI Tapered Roller Bearing1@ Bearing Spacer

Unit:mm


Standard ClearanceClearance Limit

1%Axle Clearance------

Adjust

1^Ring And Pinion Gear Backlash0.21 to 0.29 mm0.29 mm

1&Pinion Gear Preload - w/o seal ring115 to 138 Nm

1*Pinion Ring Gear Preload - w/o seal ring148 to 188 Nm

WB146-510-17

PLANETARY

10-18WB146-5B Stud BoltF Axle ShaftJ Tapered Roller BearingC Planet GearG Pressure Plate1) Oil SealD Wheel HubH Retaining Ring1! Wheel FlangeE Sun GearI Ring Nut

Unit : mm


1@Hub Rotation Torque---Adjust

1#Axle Shaft Clearance---

WORK BRAKES

B Bleed Screw

E Middle Plate

H Bushing

C Brake PistonF Outer PlateI Parking Brake Control Caliper

D Friction DiscG Belleville WasherJ Set Screw

Unit : mm


1)Hub Rotation Torque---Adjust

WB146-510-19

DIFFERENTIAL LOCK

B Engagement Pin

E Piston

h Fork

C SleeveD CoverF BushingG Control Rodi Spacera Diff Lock Port

10-20WB146-5

HYDRAULIC PUMP

b

COMPONENTSHydraulic Pump

Ps From Hydraulic TankP1L From Control Valve Pp

PsOil IntakeP1L Pump Delivery Pressure Input

cDelivery Control ValvePLS From Control Valve LSP1C QD For Pump Delivery Pressure

dOil Refil PlugPM From EV1 Solenoid ValvePd2 Drain Plug

PORT CONNECTIONSPORT FUNCTIONSPen Delivery Control Pressure Check

P1To Loader ValveP1 Pump DeliveryPLS LS Signal Input

PdTo Hydraulic TankPd DrainPM Operarting Mode Control Signal

STRUCTURE, FUNCTION ANDMAINTENANCE STANDARDHYDRAULIC PUMP

WB146-510-21

MAIN PUMP

PORT FUNCTIONSPe Delivery Control SignalPd5 DrainPa Delivery Control Group FeedPd4 DrainPM2 Operating Mode Signal

10-22WB146-5

B Bearing

G Piston

1! Control Piston

C Input ShaftH Cylinder Block1@ Spring

D Pump HousingI Swash Plate1# Seal Ring

E Swash PlateJ Cover1$ Ball

F Shoe1) Shoe Guide

WB146-510-23

FUNCTION

The rotation and torque transmitted to the pump shaft is converted into hydraulic energy and pressurized oil is delivered according to the load requirements.

The amount of oil delivered can be modified by changing the angle of the swash plate.

STRUCTURE

Groove a supports and makes the cylinder block B an integral part of the shaft c. The shaft is supported by front d and rear e bearings.

The end of piston f is a concave ball, and the shoe g is staked to it to form one unit. The piston and shoe form a spherical bearing.

The swash plate h is supported by the pump body i and ball j, and has a flat surface A. The shoe g remains in contact with the swash plate and slides in a circular movement. Pressurised oil is introduced between the shoe and swash plate forming a static bearing that allows the shoes to slip.

The pistons f perform their relative movements in an axial direction, inside the cylindrical chambers fashioned in the cylinder block B.

The rotation of the cylinder block B pressurises the oil inside the chambers of the block; pressure is adjusted by the valve plate 1). The surface of the swash plate is so designed that the oil pressure always remains within acceptable limits. The oil in each chamber is drawn in and discharged through holes in the valve plate.

OPERATION Pump Operation1.The cylinder block B rotates with the shaft c, and the shoe g slides on the flat surface A. When this happens, the swash plate h rotates on the ball j, and the angle a between the axis of the cylinder block and the axis X of the swash plate changes. The angle a is known as the swash plate angle.

10-24WB146-5

2.When the axis X of the swash plate h retains the angle a in relation to the axis of the cylinder block B, flat surface A acts as a cam for the shoe g. This is why the piston f slides inside the cylinder block, creating a difference between volumes E and F and therefore causing the suction and delivery of oil in a quantity that is equivalent to the difference between those volumes (F E = delivery). When the cylinder block rotates, chamber F decreases in volume causing oil to be delivered to the circuits, while chamber E increases in volume causing oil to be suctioned. The illustration shows the state of the pump when suction at chamber F and delivery at chamber E are complete.

3.When the center line X of the swash plate h and the center line of the cylinder block B are perfectly aligned, the swash plate angle a= 0, the difference between the volumes E and F within the cylinder block becomes 0 and the pump does not take in or deliver any oil. The angle of the swash plate a is proportional to pump delivery.

Control of Delivery

1.When angle a of the swash plate increases, the difference between volumes E and F increases too, and this makes delivery Q increase accordingly. Angle a of the swash plate is varied by the servo piston 1!.

2.The servo piston 1! moves in a reciprocating linear motion caused by pressure signals from the PC and LS valves. The linear motion is transmitted to the swash plate h. The swash plate is supported by the pump body i through the ball j, and this is the reason why the swash plate moves in a semicircular alternate motion.

WB146-510-25

DELIVERY CONTROL VALVE

PORT FUNCTIONS

P1 Delivery Control Group Feed

PEDelivery Control Signal Output

T DrainPd4 DrainPM Operating Mode Signal Input

10-26WB146-5

COMPONENTS

i

Gasket

PORT FUNCTION

bLeverjPistonTDrain

cSpring1)SpoolPAPump Delivery Pressure

dRetainer1!PlugPMOperating Mode Signal Output

eSeal1@SeatPPLDelivery Control Signal Input

fSpool1#SpringPEDelivery Control Signal

gSleeve1$NutPLSLS Signal Input

hPiston1%PlugPPLSLS Pump Signal Input

WB146-510-27

LS VALVE FUNCTION

The LS valve controls the pump delivery according to the stroke of the control valve lever, the function of the delivery demands made by the actuators.

The LS valve detects the actuators delivery needs by means of the differential pressure UPLS existing between pressure PPLS, control valve input pressure, and pressure PLS, control valve output pressure. The sensing of this differential pressure permits control of the main pump delivery Q. PPLS, PLS and UPLS are, respec- tively, the pump pressure, the Load Sensing pressure, and the difference in pressure between these two values.

The LS valve detects the pressure difference UPLS generated by the passage of the oil flow through the surface freed by the control valve spool, and controls the pump delivery Q so as to keep the pressure drop constant. It can therefore be assumed that the pump delivery is proportional to the demands made known by the control valve.

Pump pressure PPLS, pump pressure at control valve input, and pressure PLS, Load Sensing pressure, are introduced into the LS valve. The relation between differential pressure UPLS and pump delivery varies as shown in the diagram on the right.

PC VALVE FUNCTION

The PC, Power Control, valve performs an approximate power check, and ensures that the hydraulic horsepower absorbed by the pump does not exceed the horsepower delivered by the endothermal engine.

This is achieved by limiting the pump delivery Q function of the delivery pressure PPLS, even if the LS valve requests an increase in delivery Q due to the larger section freed by the control valve spool, in the presence of high pressure pump delivery.

When during operation the delivery Q increases and the delivery pressure PPLS also increases simultaneously, the PC valve reduces the pump delivery Q. When the delivery pressure PPLS decreases, the PC valve increases the pump flow.

As pressure PC increases, the relation between pressure PA and delivery Q is switched in accordance with the force applied by pressure PC.

When the force applied by pressure PC is added to the force applied by the pump's delivery pressure against the spool f, the relation between pump delivery pressure and delivery is switched from b to in accordance with increment X.

10-28WB146-5

PC VALVE OPERATION Spring Operation PC valve spring loading d is defined by swash plate position.

If control piston g moves to the right, spring d is compressed by the lever c and the spring load increases.

When Pump Pressure PA is Low

The force applied by the pressure against the spool e decreases, and the spool f shifts slightly to the right. At the same time, a connection opens between ports C and D, and pressurised oil from valve LS is sent for discharge, PT.

Simultaneously, ports F and G on valve LS are interconnected, and pressure at port J is sent for relief, PT; the control piston c shifts to the left. Pump delivery increases as a result.

When the control piston c moves, the lever d moves to the left, and the spring b expands, thereby reducing its load on the spool f. Con- sequently, the spool moves to the left and stops the oil flow between ports C and D, and a passage opens between ports B and C. The pressure at port C increases, and the control piston stops.

WB146-5110-29

When Pump Pressure PA Is High

The force applied by the pressure against the spool e increases, and the spool f shifts slightly to the left. At the same time, a connection opens between ports C and B, and the pressure of the oil sent to valve LS becomes equivalent to the pump's delivery pressure, PA.

Simultaneously, ports F and G on valve LS are interconnected, and pressure at port J becomes equivalent to the pump's delivery pressure, PA, and the control piston c shifts to the right. Pump delivery decreases as a result.

When the control piston c moves, the lever d moves to the right, and the spring b compresses, thereby increasing its load on the spool f. Consequently, the spool moves to the right and stops the oil flow between ports C and B, and a passage opens between ports D and C. The pressure at port C decreases, and the control piston c stops.

10-30 1WB146-5

When Equilibrium Has Been Reached

The equilibrium between the force applied by pressure PA against spool e and the force applied by spring b against spool f is what determines the position at which the control piston c, pump stops.

WB146-5110-31

MAIN CONTROL VALVE

STRUCTURE, FUNCTION ANDMAINTENANCE STANDARDMAIN CONTROL VALVE

10-32 1WB146-5

B5A1Arm Cylinder RodB8Loader Boom Cylinder RodPA6Solenoid Valve EV1, A1 PortA2Swing Cylinder HeadB9Right Outrigger Cylinder RodPA7Solenoid Valve EV2, A2 PortA3Loader Bucket Cylinder HeadB10Left Outrigger Cylinder RodPA8Loader PPC Valve, P3 PortA4Backhoe Boom Cylinder HeadLSHydraulic Pump, PLS PortPA9Outrigger PPC Valve, P1 PortA5Backhoe Bucket Cylinder RodPHydraulic Pump, P1 PortPA10 Outrigger PPC Valve, P3 PortA6Mp Bucket Cylinder HeadDSteering Unit, P PortPB1Left Backhoe PPC Valve Port 1A7Jig Arm Cylinder HeadDLSSteering Unit, LS PortPB2Left Backhoe PPC Valve Port 2A8Loader Boom Cylinder HeadPPHydraulic Pump, P1L PortPB3Loader PPC Valve, P1 PortA9Right Outrigger Cylinder Head TDrainPB4Right Backhoe PPC Valve Port 1A10Left Outrigger Cylinder HeadTSDrainPB5Right Backhoe PPC Valve Port 2B1Arm Cylinder HeadPPPC Solenoid Valve EV1, P PortPB6Solenoid Valve EV1, B1 PortB2Swing Cylinder RodPA1Left Backhoe PPC Valve Port 3 PB7Solenoid Valve EV2, B2 PortB3Loader Bucket Cylinder RodPA2Left Backhoe PPC Valve Port 4 PB8Loader PPC Valve, P4 PortB4Backhoe Boom Cylinder RodPA3Loader PPC Valve, P2 PortPB9Outrigger PPC Valve, P1 PortB5Backhoe Bucket Cylinder Head PA4Right Backhoe PPC Valve Port 3 PB10 Outrigger PPC Valve, P4 PortB7Mp Bucket Cylinder RodPA5Right Backhoe PPC Valve Port 4

WB146-5110-33

B ACV - Jig Arm Extend

1) ASCV - Loader Bucket Curl

1( Backhoe Boom Spool

C ACV - Backhoe Bucket Curl1! ACV - Backhoe Boom Lower2) Loader Bucket Spool

d ASCV - Backhoe Boom Raise1@ ACV - Backhoe Bucket Dump2! Backhoe Swing Spool

e ACV - Loader Bucket Dump1# ACV - Jig Arm Retract2@ Backhoe Arm Spool

f ASCV - Backhoe Left Swing1$ ACV - MP Loader Bucket Dump2# Priority Valve Spool

g ACV - Backhoe Arm Out1% Loader Boom Arm Spool2$ Unloading Valve

h Safety Valve1^ Jig Arm Spool2% LS By Pass Plug

i ACV - Backhoe Arm In1& MP Bucket Spool

j ASCV - Backhoe Right SwingACV - Anti-Cavitation Valve1* Backhoe Bucket SpoolASCV - Anti-Shock/Cavitation Valve

10-34 1WB146-5

Unit : mm

Check ItemSpring Criteria

Remedy

Standard SizeRepair Limit

Free LengthInstalled LengthInstalled LoadFree LengthInstalled Load

2^Backhoe Arm In Spool Spring24.223.730.4 N--24.3N

Replace

2&Backhoe Arm Out Spool Spring27.226.730.38 N--24.3 N

2*Prioroty Valve Spring56.848.529.6 N--23.7 N

2(Unloading Valve Spring25.518.0121.5 N--97.2 N

3)Backhoe Swing Spool Spring29.028.522.5 N--18.0 N

3!Loader Bucket Spool Spring42.340.554.9 N--43.9 N

3@Backhoe Boom Spool Spring41.140.534.3 N--27.4 N

3#Backhoe Bucket Spool Spring41.140.534.3 N--27.4 N

3$MP Bucket Spool Spring29.028.522.5 N--18.0 N

3%Backhoe Jig Spool Spring29.028.522.5 N--18.0 N

3^Loader Boom Raise Spool Spring27.126.714.7 N--11.8 N

3&Loader Boom Lower Spool Spring38.727.6355.7 N--284.5 N

3*Loader Boom Float Spool Spring19.419.014.7 N--11.8 N

Unit : mm


Remedy



2*PDV Tension Spring15.48.07.44 N--5.96 N

Replace

2(PDV Tension Spring31.421.863.7 N--51.0 N

3)PDV Tension Spring18.915.015.7 N--12.5 N

3!PDV Tension Spring37.124.034.3 N--27.4 N

3@PDV Tension Spring20.015.04.32 N--3.45 N

3#Check Valve Spring27.221.04.7 N--3.76 N

3$Check Valve Spring27.222.03.92 N--3.14 N

3%Check Valve Spring21.915.81.96 N--1.57 N

WB146-5110-35

Pressure Reducing ValveB Loader Boom

Delivery Control Valvej Backhoe Arm

1* Check Valve1( Check Valve

C Backhoe Jig Arm1) Backhoe Swing2) Check Valve

d MP Bucket1! Loader Bucket2! Check Valve

e Backhoe Bucket1@ Backhoe Boom2@ Check Valve

f Backhoe Boom1# Backhoe Bucket2# Check Valve

g Loader Bucket1$ MP Bucket2$ Check Valve

h Backhoe Swing1% Backhoe Jig Arm2% Check Valve

i Backhoe Arm1^ Loader Boom2^ LS By Pass Plug

1& Main Relief Valve2& LS, DLS Pressure Check Valve

10-36 1WB146-5

b Backhoe Right Outrigger Spoole Backhoe Swing SpoolH Backhoe Boom Spoolc Backhoe Left Outrigger Spoolf Loader Boom Spoold Loader Bucket Spoolg Backhoe Bucket Spool

Unit : mm


Remedy



iOutrigger Spool Outer Spring18.017.539.2 N--31.4 NReplace

jOutrigger Spool Inner Spring20.210.430.4 N--24.3 N

WB146-5110-37

b PPC Maximum Pressure Valvee Blow Out PlugH Arm Spoolc Maximum Pressure Valve Spoolf Unloading Valved Sequential Reducing Valveg LS By Pass Plug

Unit : mm


Remedy



iOutrigger Spool Outer Spring18.017.539.2 N--31.4 NReplace

10-38 1WB146-5

CLSS

DESCRIPTION

CHARACTERISTICS

The term CLSS means Closed center Load Sensing System, which has the following characteristics:

High precision control that is independent of the load applied to the movement;

High precision control of digging action even during delicate ma- noeuvres.

Ability to perform complex operations, guaranteed by control of oil flow in function of the aperture surfaces of the shuttles.

Energy savings guaranteed by control of pump delivery.

STRUCTURE

The CLSS system includes the variable flow pump, the control valve and the working equipment.

The pump includes the main pump, the PC valve and the LS valve.

STRUCTURE, FUNCTION ANDMAINTENANCE STANDARDCLSS

WB146-5110-39

OPERATING PRINCIPLES

PUMPING PLATE CONTROL ANGLE

The angle of the swash plate and the pump delivery, is controlled in such a way that the differential pressure UPLS between the delivery pressure PP of the pump and the pressure PLS at the outlet of the control valve towards the actuator is maintained at a constant value. UPLS= pump delivery pressure PP minus pressure PLS of delivery to the ac-tuator.

If the differential pressure UPLS becomes lower than the set pressure of the LS valve, the angle of the swash plate increases, delivery increasing.

If the differential pressure UPLS increases, the angle of the swash plate decreases.

10-40 1WB146-5

PRESSURE COMPENSATION CONTROL

The pressure compensation valves are installed downstream from the control valve in order to balance the differential pressure between the loads. When two or more movements, cylinders, are activated simultaneously, the pressure differences UP between the delivery at the control valve inlet and outlets of the control valve are compensated by these valves. This will obtain the distribution of the pump flow in proportion to the areas of passage S1 and S2 of each valve.

WB146-5110-41

MAIN CONTROL VALVE

1.Unloading Valve Pressure ................................. LS + 28.02 kg/cm

2.Main Pressure Relief Valve ........................................ 222.14 kg/cm

3.Safety Valve ............................................................... 275.13 kg/cm

4.Check Valve

5.Anti Shock/Cavitation Valve...................................... 219.08 kg/cm



8.Pressure Compensation Valve

9.Priority Valve

10. PPC Reducing Vave

10-42 1WB146-5

UNLOADING VALVE Neutral Position FUNCTION When the control valve is in NEUTRAL position, pump delivery Q,resulting from the swash plate being at its min. angle, is sent into the tank circuit. When this happens, the pump's delivery pressure PP is regulated at 28 kg/cm by means of the spring c inside the valve. LS signal with PLS pressure = 0 kg/cm .

OPERATING

Pump pressure PP acts on spool b on surface S1, and on surface S2, whereas PLS pressure acts on surface S2. Since no LS signal with PLS pressure is generated when the control valve is in NEU- TRAL position, the only pressure acting on spool in this condition is the pump's delivery pressure PP as regulated by spring compression c.

As the pump's delivery pressure PP increases and the resulting force equals spring loading c, the spool b shifts to the right. The pump's delivery circuit PP is then connected to the tank circuit T by means of the holes in spool. This ensures that the pump delivery pressure PP stays regulated at 28 kg/cm.PP .................................................................................Pump circuit PLS ................................................................. Load Sensing circuit T..................................................................................... Tank circuit

WB146-5110-43

Control Valve Fine Control

FUNCTION

When the actuators' delivery needs during fine control are within the delivery values related to the minimum angle of the swash plate, the pump's delivery pressure PP is regulated by pressure PLS at +28 kg/ cm. Since the unloading valve opens when the differential pressure between the pump's delivery pressure PP and pressure PLS of theLS equals spring load c, 28 kg/cm, the differential pressure UPLS be-comes 28 kg/cm.

OPERATING

When fine controls are performed at the control valve, a PLS pressure is generated. This pressure acts on surface S3 on the right hand side of the spool b. Since pressure PLS of LS is low, because the control valve passage is small, the difference with the pump's delivery pressure PP is great.

When the differential pressure between the pump's delivery pressure PP and pressure PLS of the LS equals spring loading c 28 kg/cm, the spool b shifts to the right and, in turn, the pump circuit PP con- nects to the tank circuit T.

The pump's delivery pressure PP is regulated by the combination of the pressure from the spring, 28 kg/cm, and the pressure PLS of the LS, when the differential pressure UPLS reaches a value of 28 kg/ cm.

10-44 1WB146-5

Control Valve Is In Use

FUNCTION

When the request for oil flow from the actuators exceeds the minimum delivery of the pump during use of the control valve, the connection to the tank circuit is eliminated and the entire pump delivery Q is sent to the actuators.

OPERATING

When the control valve spool is caused to perform a longer travel, this generates a pressure PLS of the LS, which acts on the right side of the spool b. Since the control valve passage is wide, the difference between the pressure PLS of the LS and the pump's delivery pressure PP is small.

For this reason, since the differential pressure between the pump's delivery pressure PP and the pressure PLS of the LS fails to reach the spring loading pressure value of spring c 28 kg/cm, the spool b is pushed to the left by the spring.

The result is that the connection between the pump delivery circuit PP and the tank circuit T is excluded and the entire pump delivery Q is sent to the actuators.

WB146-5110-45

LS PRESSURE Function LS pressure is the actuator's pressure at control valve output. This pressure actually reduces the pump's PP pressure via the pressure compensation group reducing valve D to the same A pressure of the actuator circuit and then sends it into the PLS circuit of the LS. In the outriggers control valve, the actuator's pressure A is introduced directly into circuit PLS of the LS.

Operation w/o Outriggers

When the spool B is operated, pump pressure PP starts flowing into the circuit of actuator A from the delivery control valve C and from the notch a via the duct b. At the same time, the pressure reducing valve D moves to the right making the pump's pressure PP drop as it flows through the bottleneck c, and causing the pressure to flow into the circuit PLS of the LS and into the chamber of spring PLSS. At this point, the PLS circuit of the LS is connected to the tank circuit T by means of the by pass plug E.

The pressure acting on the left side of the reducing valve D is pressure PA of the actuator, and the pressure acting on the right hand side is the reduced pressure PP of pump delivery. The reducing valve bal- ances out when pressure PA of the actuators and pressure PLSS of the spring chamber are balanced. This in turn allows the pressure PP, now reduced by the bottleneck c, to be introduced into the PLS circuit of the LS at the same pressure A as the actuator's circuit.

10-46 1WB146-5

Operation w/o Outriggers

When the spool b is operated, pump pressure PP starts flowing into the circuit of actuator A through the duct a.

At the same time, pressurised oil is introduced into the PLS circuit of the LS through holes b.

The outriggers circuit differs from the working equipment circuit in that the operating pressure of ctuator A is introduced directly into the PLS circuit of the LS.

WB146-5110-47

LS BY PASS PLUG Description The LS by pass plug unloads residual pressure from the load sensing's PLS circuit.

This makes the increment rate of load sensing's PLS pressure smoother. By eliminating oil, through the bottleneck, a loss of pressure is generated in the flow that is controlled by the spool, and sta- bility is increased as a result, thereby reducing the actual differential pressure LS.

Operation

Pressurised oil in the Load Sensing PLS circuit flows through filtera, through orifice b and into the tank circuit T.

10-48 1WB146-5

PRESSURE COMPENSATION VALVES Function Pressure compensation occurs during simultaneous operation of sev- eral movements, specifically when the pressure of an actuator becomes lower than the pressure of the actuator on the opposite side, and pump delivery is on the verge of being increased. In this case, the right actuator withstands a higher pressure than the left actuator.

Operation

During operation together, when right actuator pressure increases, delivery in circuit A of the left actuator tends to increase. The PLS pressure of the LS for the right actuator acts on chamber PLS1 of the spring and pushes the pressure reducing valve b and the delivery control valve c to the left. The delivery control valve produces a bottleneck between the pump's delivery PP circuit and the PPA circuit upstream of the control valve spool. This bottleneck generates a pressure loss between circuits PP and PPA.

The delivery control valve c and the pressure reducing valve b are balanced out at a point where the differential pressure between PA and PLS, these two acting on both surfaces of the pressure reducing valve, equals the loss of pressure between PP and PPA, these two acting on both surfaces of the delivery control valve.

The differential pressure between the upstream pressure PPA and the downstream pressure of both spools in the control valves con- cerned in the movement together are equalised, and pump delivery is distributed proportionally to the sections a that are responsible for opening the notches of each spool.

WB146-5110-49

PRESSURE COMPENSATION VALVE Function In order to equalize the characteristics of each actuator, the pressure compensation valve will determine the compensation characteristics by performing a micrometer adjustment of the surface ratio S1/S2. This is the ratio of area S1, delivery control valve c end, to area S2, pressure reducing valve b end.S1 surface of delivery control valve c minus surface of piston d.S2 surface of pressure reducing valve b minus surface of piston d.

Compensation Characteristics

When the ratio is 1.00 : Pump pressure PP minus pressure PPA upstream of spool load sensing PLS pressure - actuator PA pressure(= A). Delivery is distributed proportionally to the opening surfacesof the spool. When the ratio is > 1.00: PP - PPA > PLS - PA (= A). Delivery distribution is lower than the proportion of the opening surfaces of the spool. When the ratio is < 1.00: PP - PPA < PLS - PA (= A). Delivery distribution is higher than the proportion of the opening surfaces of the spool.

10-50 1WB146-5

PRIORITY VALVE Function The purpose of the priority valve is to feed pressurised oil to the steering unit and to the other actuators. Oil di

shop manual wb146 5

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