36 T I R E R E V I E W - May/2012

This article on Basic Tire Demounting and Mountingis the second in TIRE REVIEW’s four-part Back2Basicsseries covering the basic tire-related tasks per-formed in today’s tire shops. The first in this serieswas on Basic Tire Repair and appeared in ourFebruary 2012 issue. This article on the basic process of demounting atire from a wheel and mounting a new tire shouldbe helpful not only to newly trained tire technicians,but also veterans who want to brush up on theirtechniques. The information presented here is a compilation of

recommended industry procedures with informationprovided by major tire changer manufacturers andmarketers. We have attempted to simplify the pro-cedures for this article, but readers should under-stand that each equipment maker has its ownequipment-specific procedures and instructions.These usually are based on the unique attributes ofeach piece of equipment.The photos for this article were shot in the Auto -motive Technology Center of Stark State College inNorth Canton, Ohio, with the cooperation and assis-tance of Jim Olszewski of Hunter Engineering Co.

22Back2Basics By Tom Duke

Contributing Editor

Step-by-StepTIRE DEMOUNTING/

MOUNTING

How tHe Simple HaSBecome complex

With this installment, our Back2 -Basics series looks at an essential partof the tire sales and service process:demounting an old tire and mountinga new one on the customer’s vehicle.

And while it is the most basic ofprocedures for any tire shop, whatused to be a rather simple process hasbecome increasingly complex, withmore and more sophisticated equip-ment being used. Today’s newerequipment has made the processmore precise for the customer andoften easier on the backs and legs oftire techs, but fundamentals of gettinga tire off and on a wheel remain thesame.

There are many manufacturers oftire changing equipment that makemodels from the very basic to themore sophisticated that will almost dothe job automatically. Some of thebrands on the market include Hunter,Hennessy/Ammco-Coats, Corghi,Coseng, Eagle, Hoffman/Snap-On,John Bean/Snap-On, Ranger, Tescoand Tire Service Equipment, amongothers.

Begin at tHe BeginningGenerally speaking, there are two

basic types of tire changers: the table-top or rim clamp style, and the centerpost style.

There are tabletop/rim clamp chan -

g ers that will do a fine job in anydealership, and there are more auto-mated models and changers that spe-cialize in handling high performanceand UHP tires. Some tabletop modelswill automatically lock to presetwheel diameter and width positions.

The more expensive automatedmodels – like the center-post stylechanger above – can handle tires ofvarious diameters and feature a high-torque motor. These changers canmount and demount tires without theuse of hand-held levers, whichrelieves the stress on the beads andthe operator. This particular modelcan be adjusted to three differentheights to allow the technician towork at the most effective position.Switches and foot pedals control vir-tually all tire changing operations,which ensures the same simple opera-tion on all assemblies regardless ofthe size, design or fitment.

Some changers are designed to han-dle the largest wheel assemblies, in -cluding ultra low profile high per-formance and ultra-high performancetires. An articulated mounting armallows the polymer mounting head tofollow the rim flange edge. The poly-mer head helps protect against mar-ring damage on custom and high-endOE wheels, and reduces the stress tobeads on stiff, low-profile tires. Anoptional pneumatic wheel lift helpstechnicians mount tires effortlessly,preventing potential injuries and

fatigue from manually lifting heavywheels into place.

Let’s look at the steps involved in abasic, generic tire removal using atabletop tire changer.

tHe tire removalproceSS includeS:

• Loosening the beads• Clamping the tire/wheel

assembly to a tire changer • Demounting the upper bead • Demounting the bottom bead

inStalling a new tireon a wHeel includeS:

• Lubing both beads • Installing the bottom bead • Installing the upper bead • Seating the beads with air

pressure • Inflating to the proper PSI

Sounds simple, right? But with thescores of different types of machinerybeing offered by major equipmentmanufacturers to make the job easier,it can become confusing and complex.

wHat to look ForThe number one item that a tire

technician should do is identify thetype of wheel involved and how a tireshould be changed on that particularwheel. This includes understanding

May/2012 - t i r e r e v i e w . c o m 37

By Tom Duke

Contributing Editor

Typical tabletop tire changer with pedal andbutton controls.

This automated center-post style changer willhandle wheels up to 34 inches in diameter.

This top-of-the-line changer accommodatesvirtually any wheel and tire assembly.

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whether it is a standard or reversemount rim, the construction mat -erial of the wheel, the dimension-al size and if any existing damageis present.

Because of differences in wheelconstruction and materials – fromcertain OE wheels to high-costaftermarket wheels – a number ofthings must be considered andchecked due to changes in somewheel constructions. A number oflight trucks and even other mod-els now have chrome-clad wheels.These wheels have a plastic coverthat can be damaged during thechanging process. Handle thesewheels more carefully. Somewheels that have painted surfacesalso are subject to damage andshould be handled with care.

SaFety FirStThere are a number of safety

measures that should be observedwhen changing a tire. Many dan-ger “warnings” are pointed outcompletely in a new wall chartissued recently by the RMA.

For example, as everyone inthis industry should know, thereis a danger of serious injury ordeath if one attempts to mount atire of one wheel diameter on awheel with a different diameter.This is most common with 16.5-inch wheel diameter wheels and16-inch wheel diameter tires, butit also is possible with many othercombinations if a tire tech fails todouble check tire and wheel sizes.

As simple as it looks, tire chan -ging is dangerous and should bedone by trained personnel usingproper tools and procedures.

Read and understand warningspublished by tire changer manu-facturers, tiremakers and wheelsuppliers, whether the informa-tion is on a placard adhered to themachine or on the tire sidewall orin support literature for a wheel.Failure to comply with these warn -ings may cause or create problemsthat could result in injury, orworse.

38 T I R E R E V I E W - May/2012

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The following “how to” photos and captions show and explain the basic procedures fordemounting and mounting tires. The process demonstrated here assumes the tire/wheelassembly has standard rubber valve stems and not stems with TPMS sensors. Under -stand that each tire changer manufacturer has specific steps for its unique equipment.Make sure you follow those specific procedures as required. Additional information aboutmounting/demounting tires is available on RMA’s website – rma.org – by requesting itsDemounting and Mounting Procedures wall chart, or by requesting information from TIA –tireindustry.org – for its Automotive Tire Service training Module 8 on Demounting,Mounting and Inflation.

Step-by-Steptire demounting/mounting procedures

demounting StepSBefore doing anything, identify the type of wheel and if there are any special handling issues.

After positioning wheel assembly on tire chang-er, remove valve core. (Note core in technician’sfingers.)

1 2

Remove any wheel weights, again being carefulnot to damage wheel.

3 4

Use breaking shovel to unseat the top bead. Turn tire/wheel assembly around and repeatusing the shovel.

5 6

Secure assembly on tire changer. In this photo,the assembly is on a tabletop or rim clamp stylechanger.

Here the assembly is being mounted on a centerpost style changer. Make sure to properly posi-tion the assembly on the center post when usingthat type of changer.

40 T I R E R E V I E W - May/2012

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operating under- or overinflatedor over loaded must be app roach -ed with caution. Ply cords weak-ened by under- or overinflationand/or over loading may breakone after another, until a ruptureoccurs in the sidewall with explo-sive force. Obviously, this canresult in serious injury or death.

Never, under any circumstan -ces, introduce a flammable –ether, propane, lighter fluid, gaso-line, etc. – substance into a tirewhen trying to seat the beads.

Silicone-, petroleum- or sol-vent-based lubricants must not beused. These substances may causethe tire to slip on the rim; have aharmful effect on the tire and/orwheel; or create explosive mix-tures of air and vapors in the tirethat may result in serious injuryor death.

When servicing tires andwheels, tire service professionalsshould always wear the appropri-ate personal protective equipment(PPE), including safety glasses,work gloves, hearing protectionand leather work shoes or boots.

diSclaimerDemounting and mounting tires

is a serious business. The precedingarticle was researched and writtenusing existing material from HunterEngineering, RMA and TIA. Thisinformation is NOT meant as asubstitute for proper training byTIA or by the equipment manufac-turer. The photos were taken withthe participation of HunterEngineering at Stark State College.The process shown here is consis-tent with those used by other majortire changer manufacturers, butconsult their specific equipment useprocedures and instructions. Thisarticle is meant purely for educa-tional purposes and those who usethe methods recommended are sole-ly responsible for any injuries orlosses resulting from their applica-tion.

Lubricate top bead.

7 8

Break top bead by pushing down using thechanger’s unique tool.

9 10

Use the changer’s lever to slip the top bead overthe rim flange.

Lift bottom bead over rim flange.

1 2

Make sure the tire size matches the wheel diam-eter and width. After securing wheel to changingmachine, check wheel for damage of any type.Also double check to see if the tire has a direc-tional tread.

Remove old rubber valve stem, being careful tonot damage the wheel. This particular toolbreaks the rubber stem into two pieces; makesure to remove the other piece from inside thedrop center of the wheel.

tire mounting StepS

demounting StepS (cont.)

Step-by-S

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3 4

Lubricate the inboard and outboard bead areas.

5 6

Place tire on wheel and with a lever securely inplace, twist the tire bead over the top rim flangeby hand.

You may need to use the changer’s mechanicallever to complete this step.

7 8

Identify the maximum air pressure for the tire.You will need that information to properly seatboth beads using air pressure.

Seat both beads using air pressure and a gentlelift of the tire up into the top rim flange.

9 10

Install a new valve core.

Find the proper inflation pressure for the tireson the vehicle placard located in the driver’sdoor jamb or the vehicle owner’s manual. Inflatethe tire to that pressure. For uniformity, deflateand then inflate again.

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mounting StepS (cont.)