006-026 Injector

Initial Check

Cummins® Common Rail Fuel System

WARNING

The fuel pump, high-pressure fuel lines, andfuel rail contain very high-pressure fuel. Donot loosen any fittings while the engine isoperating. Wait at least 10 minutes aftershutting down the engine before looseningany fittings in the high-pressure fuel systemto allow pressure to decrease to a lowerlevel.

CAUTION

Use caution when disconnecting orremoving fuel lines, replacing filters, andpriming the fuel system, that fuel is notspilled or drained into the bilge area. Do notdrop or throw filter elements into the bilgearea. The fuel and fuel filters must bediscarded in accordance with localenvironmental regulations.

CAUTION

Installation of the banjo flow adapter at anyplace other than the fuel drain manifold can

cause damage to high pressure fuel systemcomponents.

Return fuel is routed from the injectors, the fuelrail pressure relief valve, and the fuel pumphead through three different drain lines.

Measurement of fuel injector leakage requiresthe use of a fuel return hose, Part Number3164618.

The tool is used to isolate the leakage from justthe injectors, so it can be measured with agraduated cylinder.

If necessary, this tool can be constructed usingthe steps outlined below.

To make a banjo bolt flow adapter tool, drill andtap the hex face of a M12 x 1.5 banjo bolt, PartNumber 3903035, or equivalent.

Drill and tap the hex face of the banjo bolt tothe size of a male union (or other hose fitting)being used (example 1/8-inch NPT hose barb).

Drill and tap the open end of the banjo bolt forthe installation of a 5/16-24 set screw.

WARNING

Depending on the circumstance, diesel fuelis flammable. When inspecting or performing

service or repairs on the fuel system, toreduce the possibility of fire and resultingsevere personal injury, death or propertydamage, never smoke or allow sparks orflames (such as pilot lights, electricalswitches, or welding equipment) in the workarea.

CAUTION

Use caution when disconnecting orremoving fuel lines, replacing filters andpriming the fuel system that fuel is notspilled or drained into the bilge area. Do notdrop or throw filter elements into the bilgearea. The fuel and fuel filters must bediscarded in accordance with localenvironmental regulations.

Remove the M12 banjo bolt that connects thefuel injector drain line to the fuel drain manifold.

Install the M12 fuel return hose, Part Number3164618, at the fuel drain manifold.

Route the fuel return hose into a collectiondevice.

Obtain a graduated cylinder that is marked incubic centimeters; example: graduated beaker,Part Number 3823705, or equivalent. A kitchenstyle measurement cup that is marked in cubiccentimeters (cc's) also works well.

Start the engine and allow the engine to idleuntil drain fuel from the injector drain linebegins to flow into the collection container.

Connect INSITE™ electronic service tool.

If the engine will not start, these proceduresare still valid; however, the pass/failspecification is different.

If the engine will not start, drain flow must bemeasured while engaging the starter for 30seconds at a time.

Leakage Specification if Engine Will NotStartMaximum Leakage During 30Seconds of Cranking

100 cc[3.38 oz]

If the injector leakage is excessive duringcranking and the engine will not start, checkthe following:

High pressure fuel connector installation.Refer to Procedure 006-052 in Section 6.High pressure fuel connector damage.Refer to Procedure 006-052 in Section 6.Use the fuel leak test tool, Part Number3164325, to isolate injectors from the fuelrail, one at a time.

CAUTION

Fuel is at high pressure during this test. Afterconnecting the test fitting, close the enginecover and stand clear of high-pressure fuellines.

If the engine will start, the following steps willdetermine if the injector drain flow is excessive.

While the engine is operating at idle, useINSITE™ electronic service tool High PressureLeak Test to create high fuel rail pressure.INSITE™ electronic service tool will command1500 BAR [21,756 psi] fuel rail pressure whilethe engine is at idle during this test.

Record the amount of time it takes for 300 cc[10.1 oz] of fuel to flow from the injector drainline when performing INSITE™ electronicservice tool High Pressure Leak Test.

Leakage Specification With EngineoperatingMaximum Leakage During 45Seconds

300 cc [10.1oz]

If 300 cc [10.1 oz] of fuel leaks from theinjectors in less than 45 seconds, there is atleast one loose or damaged high pressure fuelconnector and/or injector.

NOTE: Fuel temperature and fuel type willinfluence this measurement. For example;as the engine is warmed up and theinjectors become hot, the leakage rate willincrease. Also, low viscosity fuels, such askerosene, will cause the leakage rate toincrease. The above specification is correctfor on-highway diesel fuels where fuel inlettemperature is less than 49°C [120°F].

After recording the fuel leakage rate, stopINSITE™ electronic service tool High PressureLeak Test and turn the keyswitch to OFF.

If injector drain flow is excessive, it will benecessary to isolate the injector(s) or fuelconnector(s) that are damaged or worn.

A loose fuel connector retaining nut results in apoor seal at the interface between the fuelconnector and the injector. This loose conditionwill result in a leak of high-pressure fuel to theinjector drain.

Verify first that the fuel connectors are properlytightened. Refer to Procedure 006-052 inSection 6.

If loose retaining nut(s) are found, test forleakage after tightening the retaining nut(s).

CAUTION

Do not install the isolation tool at the highpressure pump outlet fitting. Severe enginedamage will result. This tool must only beinstalled at the fuel rail for the purpose ofisolating the high-pressure fuel supply fromindividual injectors.

CAUTION

Make certain the keyswitch is in the OFFposition (engine not operating) whenloosening or tightening high-pressure fuellines.

Use leak test isolation tool, Part Number3164325, to isolate excessive fuel drainagefrom injectors or fuel connectors.

Isolate the injector and fuel connector for eachcylinder by installing the isolation tool at the fuelrail in place of the high-pressure fuel line thatsupplies the fuel connector.

Torque Value: 38 n.m [28 ft-lb]

Record the amount of time it takes for 300 cc[10.1 oz] of fuel to flow from the injector drainline while the engine is operating. UseINSITE™ electronic service tool High PressureLeak Test. Do this up to six (6) times, oncewhile each line is isolated.

If isolating a single injector and high-pressure

fuel connector causes the leakage time toincrease significantly compared to the rest ofthe set, that injector and fuel connector mustbe inspected.

Inspect the suspect fuel connector. Refer toProcedure 006-052 in Section 6. If the fuelconnector is not damaged, replace both theinjector and the fuel connector.

Remove the M12 diagnostic flow adapter fromthe fuel drain manifold and install the M12banjo. Refer to Procedure 006-013 in Section6.

Install all high-pressure fuel lines. Refer toProcedure 006-051 in Section 6.

Operate the engine and check for leaks.

Preparatory Steps

CAPS Fuel System

CAUTION

Attempting to remove the injector withoutfirst removing the fuel connector will causedamage to the injector body and/or fuelconnector.

Remove the rocker lever cover. Refer toProcedure 003-011 in Section 3.Remove the engine brake, if equipped.

Refer to Procedure 020-004 in Section20.Remove the fuel connector. Refer toProcedure 006-052 in Section 6.

Cummins® Common Rail Fuel System

WARNING

Batteries can emit explosive gases. Toreduce the possibility of personal injury,always ventilate the compartment beforeservicing the batteries. To reduce thepossibility of arcing, remove the negative (-)battery cable first and attach the negative (-)battery cable last.

CAUTION

Use caution when disconnecting orremoving fuel lines, replacing filters, andpriming the fuel system, that fuel is notspilled or drained into the bilge area. Do notdrop or throw filter elements into the bilgearea. The fuel and fuel filters must bediscarded in accordance with localenvironmental regulations.

CAUTION

Attempting to remove the injector withoutfirst removing the fuel connector will causedamage to the injector body and/or fuelconnector.

NOTE: All fuel system diagnosticsprocedures and component specificationshave been moved. Refer to Procedure 005-236 in Section 5.

Disconnect the batteries. Refer to

Procedure 013-009 in Section 13.Remove the rocker lever cover. Refer toProcedure 003-011 in Section 3.Remove the high-pressure fuel line. Referto Procedure 006-051 in Section 6.Remove the engine brake, if equipped.Refer to Procedure 020-004 in Section20.Remove the fuel connector. Refer toProcedure 006-052 in Section 6.Remove the exhaust rocker leverassembly. Refer to Procedure 003-008 inSection 3.

Remove

CAPS Fuel System

Remove the injector hold-down clampcapscrew that is nearest the exhaust manifoldside of the engine.

Remove the injector hold-down clamp.

Remove the high-pressure fuel connector.Refer to Procedure 006-051 in Section 6.

Use the injector puller, Part Number 3825156,to pull the injector out of the head.

Alternatively, a rocker cover capscrew can beinstalled into the top of the injector and used topull the injector from the cylinder head.

Be sure the injector seal washer is removedfrom the injector bore.

Cummins® Common Rail Fuel System

Disconnect the injector wire harness from theinjector.

Remove the two injector hold-down clampcapscrews and remove the injector hold-downclamp.

Use a small heel-bar to pry up on the injectorclamp hold-down flange (part of the injectorbody just above the cylinder head casting).

Test

Mechanical Injectors

WARNING

While testing the injectors, keep hands andbody parts away from the injector nozzle.Fuel coming from the injector is underextreme pressure and can cause seriousinjury by penetrating the skin.

Install the injectors on an injector test stand.Open the bypass valve for the pressure gauge,so the spray pattern can be checked.

Use the injector test fixture, Part Number3162269, with the injector nozzle test, PartNumber 3376946.

Operate the test stand lever quickly severaltimes to check the spray pattern of theinjectors. Verify that the correct number ofplumes are present for the number of holes inthe injector. Also pay close attention to the sizeand shape of each plume. If possible, comparethe spray pattern to that of a new injector withthe same assembly number.

NOTE: The injector spray pattern is anexcellent indicator of the nozzle holecondition. Check each plume carefully. It ispossible that only a single hole has beendamaged, resulting in degraded engineperformance.

Close the bypass valve for the pressure gaugeand operate the test stand lever to check thenozzle opening pressure. There must be agood crisp "pop" when the nozzle opens andthe pressure must be within the specificationfor the assembly number.

The injector will pop between 275 bar [3,989psi] and 300 bar [4,351 psi].

If the nozzle opening pressure is excessivelylow and/or the nozzle sprays excessive fuel,the injector needle can be sticking. The needlecan be stuck due to poor lubrication or debris.

Sometimes it is possible to unstick an injectorneedle by using the injector test stand. Openthe bypass valve for the pressure gauge andoperate the test stand lever rapidly for 10 to 20strokes.

Recheck the nozzle opening pressure andspray pattern to see if the injector has returnedto normal operation.

If the injector is still out of specification, replacethe injector.

Check the injector for drip and/or excessiveleak down. Close the bypass valve for thepressure gauge and build pressure to within 10bars [145 psi]of the opening pressure of thenozzle.

A drop of fuel must not form within 15seconds.

Disassemble

Mechanical Injectors

Place the injector in the injector clamp andremove the nozzle retaining nut.

NOTE: Injectors covered under warranty bythe manufacturer must not be repaired. Seethe manufacturer's warranty instructions.

Remove the nozzle, intermediate plate, spring,and shims from the injector.

Clean and Inspect for Reuse

WARNING

When using solvents, acids, or alkalinematerials for cleaning, follow themanufacturer's recommendations for use.Wear goggles and protective clothing toavoid personal injury.

WARNING

Some solvents are flammable and toxic.Read the manufacturer's instructions beforeusing.

CAUTION

Do not use any abrasives (such as glassbeading, sand paper, emery cloth, Scotch-Brite™ pads, etc) or metallic items (includingwire brushes made of any metallic material)to clean the injectors. The use of anycleaning method other than safety solventand a soft, clean, lint-free cloth will damagethe nozzle holes and cause performanceissues.

Clean the injector tip and body with safetysolvent and a soft, clean cloth.

Assemble

Mechanical Injectors

Clean the injector internal components with

clean diesel fuel and a clean cloth. Make surethere is no debris in the internal parts of theinjector.

Install shims, as necessary, to modify thenozzle opening pressure. More shims raise thenozzle opening pressure, fewer shims lower thenozzle opening pressure.

Install the spring, button, intermediate plate,and nozzle/needle.

Make sure the intermediate plate is in thecorrect orientation with the supply hole on theplate lining up with the supply hole on theholder.

Install the retaining nut finger tight. Place theinjector in the injector clamp and tighten theretaining nut. Install the sealing washer andbody o-ring.

Torque Value: 47 n.m [35 ft-lb]

Install

CAPS Fuel System

NOTE: If a new injector is being installed, anew fuel connector must be used

Make sure the injector bore is clean and thatonly one (1) sealing washer is installed on theinjector nozzle.

Lubricate the injector o-ring with clean engineoil.

Place the injector in the head in the properorientation.

Place the injector hold-down clamp on top ofthe injector and make sure the injector is fullyseated in the injector bore.

Install the injector hold-down clamp and tighten.

Torque Value: 10 n.m [89 in-lb]

Cummins® Common Rail Fuel System

Make sure the injector bore is clean and thatonly one (1) sealing washer is installed on theinjector nozzle.

Lubricate the injector o-ring with clean engineoil.

Place the injector in the cylinder head in theproper orientation (fuel inlet toward the high-pressure fuel connector).

Use the injector shipping sleeve to make surethe injector is seated in the injector bore.

NOTE: If a new injector is being installed, anew fuel connector must be used.

Start the injector hold-down clamp capscrews,and tighten hand-tight.

Install the high-pressure fuel connector, makingsure the end of the high-pressure fuelconnector is in the injector inlet port.

NOTE: The high-pressure fuel connectorshould click into place if it is seated in theinjector inlet port correctly.

Start the high-pressure fuel connector retainingnut and tighten partially.

Torque Value: 15 n.m [133 in-lb]

NOTE: This is not the final torque for thehigh-pressure fuel connector retaining nut.

Tighten the injector hold-down clampcapscrews.

NOTE: Make sure to tighten the hold-downclamp capscrews evenly. Check to makesure the gap between the hold-down clampand the injector is equally spaced aroundthe injector body.

Torque Value: 10 n.m [89 in-lb]

Tighten the high pressure fuel connectorretaining nut.

Use the following procedure for the final torque

value. Refer to Procedure 006-052 in Section 6.

NOTE: The high-pressure fuel connectormust be properly tightened or an internalfuel leak can result, causing poor engineperformance. A torque wrench must beused.

CAUTION

Do not overtighten the injector harness. Theinjector terminals will be damaged ifexcessively over-tightened.

Install the injector wiring harness to the injector.

Torque Value: 1.25 n.m [11 in-lb]

NOTE: Orient the injector wires so they willnot interfere with a rocker lever or enginebrake housing. If the rocker lever is able tocome into contact with the injector harness,it will rub through the wire insulation andcause injector circuit fault codes.

NOTE: Polarity of the wiring is notsignificant. The signal and return wires canbe connected to either injector terminal.

Finishing Steps

CAPS Fuel System

Install the fuel connector. Refer toProcedure 006-052 in Section 6.Install the rocker lever cover. Refer toProcedure 003-011 in Section 3.Install the high pressure fuel lines. Referto Procedure 006-051 in Section 6.Operate the engine and check for leaks.

Cummins® Common Rail Fuel System

WARNING

Batteries can emit explosive gases. Toreduce the possibility of personal injury,always ventilate the compartment beforeservicing the batteries. To reduce thepossibility of arcing, remove the negative (-)battery cable first and attach the negative (-)battery cable last.

Install the exhaust rocker lever assembly.Refer to Procedure 003-008 in Section 3.Install the engine brake, if equipped.Refer to Procedure 020-004 in Section20.Install the high pressure fuel lines. Referto Procedure 006-051 in Section 6.Install the rocker lever cover. Refer toProcedure 003-011 in Section 3.Open the fuel supply and return valves.Refer to the OEM service manual.Connect the batteries. Refer to Procedure013-009 in Section 13.Operate the engine and check for leaks.

Last Modified: 02-Apr-2015

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