brake DODGE RAM 2002 Service Owner's Guide

REMOVAL
(1) Raise and support the vehicle.
(2) Position a suitable lifting device under the
axle.
(3) Secure axle to device.
(4) Remove the wheels and tires.
(5) Remove the RWAL sensor from the differential
housing, if necessary.
(6) Disconnect the brake hose at the axle junction
block.
(7) Disconnect the parking brake cables and cable
brackets.
(8)
Disconnect the vent hose from the axle shaft tube.
(9) Mark the propeller shaft and companion flange
for installation alignment reference.
(10) Remove propeller shaft.
(11) Disconnect shock absorbers from axle.
(12)
Remove the spring clamps and spring brackets.
(13) Separate the axle from the vehicle.
INSTALLATION
(1) Raise the axle with lifting device and align to
the leaf spring centering bolts.
(2) Install the spring clamps and spring brackets.
(3) Install the shock absorbers.
(4) Install the RWAL sensor to the differential
housing, if necessary
(5) Install the parking brake cables and cable
brackets.
(6)
Install the brake hose to the axle junction block.
(7) Install axle vent hose.
(8) Install the propeller shaft with reference marks
aligned.
(9) Install the wheels and tires.
(10) Add gear lubricant, if necessary. Refer to
Specifications for lubricant requirements.
(11) Remove lifting device from axle and lower the
vehicle.
ADJUSTMENTS
Ring and pinion gears are supplied as matched
sets only. The identifying numbers for the ring and
pinion gear are etched into the face of each gear (Fig.
4). A plus (+) number, minus (±) number or zero (0) is
etched into the face of the pinion gear. This number
is the amount (in thousandths of an inch) the depth
varies from the standard depth setting of a pinion
etched with a (0). The standard setting from the cen-
ter line of the ring gear to the back face of the pinion
is 147.625 mm (5.812 in.). The standard depth pro-
vides the best teeth contact pattern. Refer to Back-
lash and Contact Pattern Analysis Paragraph in this
section for additional information.
Compensation for pinion depth variance is
achieved with select shims. The shims are placed
under the inner pinion bearing cone (Fig. 5).If a new gear set is being installed, note the depth
variance etched into both the original and replace-
ment pinion gear. Add or subtract the thickness of
the original depth shims to compensate for the differ-
ence in the depth variances. Refer to the Depth Vari-
ance charts.
Note where Old and New Pinion Marking columns
intersect. Intersecting figure represents plus or
minus amount needed.
Note the etched number on the face of the drive pin-
ion gear (±1, ±2, 0, +1, +2, etc.). The numbers represent
Fig. 4 PINION GEAR ID NUMBERS
1 - PRODUCTION NUMBERS
2 - PINION GEAR DEPTH VARIANCE
3 - GEAR MATCHING NUMBER
Fig. 5 SHIM LOCATIONS
1 - PINION BEARING PRELOAD SHIM
2 - DIFFERENTIAL BEARING SHIM
3 - PINION GEAR DEPTH SHIM
3 - 112 REAR AXLE - 286RBIBR/BE
REAR AXLE - 286RBI (Continued)

AXLE SHAFTS
REMOVAL
(1) Remove the axle shaft flange bolts.
(2) Slide the axle shaft out from the axle tube.
INSTALLATION
(1) Clean the gasket contact surface area on the
flange with an appropriate solvent. Install a new
flange gasket and slide the axle shaft into the tube.
(2) Install the bolts and tighten to 129 N´m (95 ft.
lbs.).
AXLE BEARINGS
REMOVAL
(1) Remove wheel and tire assembly.
(2) Remove brake drum.
(3) Remove the axle shaft.
(4) Remove the lock wedge and adjustment nut.
Remove adjustment nut with Socket DD-1241-JD.
(5) Remove the hub assembly. The outer axle bear-
ing will slide out as the hub is being removed.
(6) Drive grease seal and inner bearing out of the
hub with Installer 5064 and Handle C-4171.
(7) Remove bearing cups from the hub with a
brass drift and a hammer.
INSTALLATION
(1) Thoroughly clean both axle bearings and inte-
rior of the hub with an appropriate cleaning solvent.
(2) Install bearing cups with Installer 8153 and
Handle C-4171.
(3) Pack inner and outer bearings with Mopar
wheel bearing grease or equivalent
(4) Apply lubricant to surface area of the bearing
cup.
(5) Install inner axle bearing in the hub.
(6) Install anewbearing grease seal with
Installer 8152 and Handle C-4171.
(7) Inspect bearing and seal contact surfaces on
the axle tube spindle for burrs and/or roughness.
Remove all the rough contact surfaces from the axle
spindle.
CAUTION: Do not let grease seal contact the axle
tube threads during installation.
(8) Carefully slide the hub onto the axle.
(9) Install outer axle bearing.
(10) Install hub bearing adjustment nut with
Socket DD-1241±JD.
(11) Tighten adjustment nut to 163-190 N´m (120-
140 ft. lbs.) while rotating the wheel.(12) Loosen adjustment nut 1/8 of-a-turn to pro-
vide 0.001-inch to 0.010-inch wheel bearing end play.
(13) Tap the locking wedge into the spindle key-
way and adjustment nut.
NOTE: Locate locking wedge in a new position in
the adjustment nut.
(14) Install axle shaft and brake drum.
(15) Install wheel and tire assembly.
PINION SEAL
REMOVAL
(1) Raise and support the vehicle.
(2) Mark the universal joint, pinion yoke, and pin-
ion shaft for installation reference.
(3) Disconnect the propeller shaft from the pinion
yoke. Secure the propeller shaft in an upright posi-
tion to prevent damage to the rear universal joint.
(4) Remove wheel and tire assemblies.
(5) Remove brake calipers to prevent any drag.
The drag may cause a false bearing preload torque
measurement.
(6) Rotate pinion yoke three or four times.
(7) Record the amount of torque necessary to
rotate the pinion gear with an inch pound dial-type
torque wrench.
(8) Hold the yoke with Holder 6719A and remove
the pinion shaft nut and washer.
(9) Remove yoke from the pinion with Remover
C-452 (Fig. 22).
(10) Remove pinion shaft seal with suitable pry
tool or slide-hammer mounted screw.
Fig. 22 Yoke Removal
1 - PINION YOKE
2 - REMOVER
BR/BEREAR AXLE - 286RBI 3 - 123

INSTALLATION
(1) Clean the seal contact surface in the housing
bore.
(2) Apply a light coating of gear lubricant on the
lip of pinion seal.
(3) Installnewpinion shaft seal with an appropri-
ate Installer.
(4) Position pinion yoke on the end of the shaft
with the reference marks aligned.
(5) Install the yoke with Installer D-191 and Yoke
Holder 6719A (Fig. 23).
(6) Install the pinion yoke washer and nut.
(7) Hold pinion yoke with Yoke Holder 6719A and
tighten shaft nut to 597 N´m (440 ft. lbs.) (Fig. 24).
Rotate pinion shaft several revolutions to ensure the
bearing rollers are seated.
(8) Rotate pinion shaft using an inch pound torque
wrench. Rotating resistance torque should be equal
to the reading recorded, plus a small amount for the
drag the new seal will have (Fig. 25).
NOTE: The bearing rotating torque should be con-
stant during a complete revolution of the pinion. If
the rotating torque varies, this indicates a binding
condition.
(9) Install propeller shaft with the installation ref-
erence marks aligned.
(10) Install the brake calipers.(11) Add gear lubricant to the differential housing,
if necessary.
Fig. 23 Pinion Yoke Installation
1 - INSTALLER
2 - YOKE HOLDER
Fig. 24 Tightening Pinion Shaft Nut
1 - DIFFERENTIAL HOUSING
2 - YOKE HOLDER
3 - TORQUE WRENCH
Fig. 25 Pinion Rotating Torque
1 -TORQUE WRENCH
2 - PINION YOKE
3 - 124 REAR AXLE - 286RBIBR/BE
PINION SEAL (Continued)

(12) Fill the differential with Mopar Hypoid Gear
Lubricant or equivalent to bottom of the fill plug
hole.
(13) Install fill hole plug and tighten to 34 N´m (25
ft. lbs.).
(14) Remove support and lower vehicle.
DIFFERENTIAL - TRAC-LOK
DIAGNOSIS AND TESTING - TRAC-LOKT
The most common problem is a chatter noise when
turning corners. Before removing a Trac-lokŸ unit
for repair, drain, flush and refill the axle with the
specified lubricant. A container of Mopar Trac-lokŸ
Lubricant (friction modifier) should be added after
repair service or during a lubricant change.
After changing the lubricant, drive the vehicle and
make 10 to 12 slow, figure-eight turns. This maneu-
ver will pump lubricant through the clutches. This
will correct the condition in most instances. If the
chatter persists, clutch damage could have occurred.
DIFFERENTIAL TEST
The differential can be tested without removing the
differential case by measuring rotating torque. Make
sure brakes are not dragging during this measure-
ment.
(1) Place blocks in front and rear of both front
wheels.
(2) Raise one rear wheel until it is completely off
the ground.
(3) Engine off, transmission in neutral, and park-
ing brake off.
(4) Remove wheel and bolt Special Tool 6790 or
equivalent tool to studs.
(5) Use torque wrench on special tool to rotate
wheel and read rotating torque.
(6) If rotating torque is less than 22 N´m (30 ft.
lbs.) or more than 271 N´m (200 ft. lbs.) on either
wheel the unit should be serviced.
DISASSEMBLY
The Trac-Loktdifferential on this axle has a one-
piece cross shaft and uses one dished disc, regular 5
disc and 7 plates.
NOTE: Pay attention to the clutch pack arrangement
during disassembly. Note the direction of the con-
cave and convex side of the plates and discs.
(1) Mark the ring gear half and cover half for
installation reference (Fig. 35).
(2) Remove case attaching bolts and remove the
button cover half (Fig. 36).
(3) Remove top clutch pack.
(4) Remove top side gear clutch ring.(5) Remove top side gear.
(6) Remove pinion mate gears and cross shaft.
(7) Remove the same parts listed above from the
ring gear flange half of the case. Keep these parts
Fig. 35 CASE MARKED
1 - REFERENCE MARKS
Fig. 36 COVER HALF REMOVAL
1 - CLUTCH PLATES
2 - BUTTON HALF
3 - FLANGE HALF
3 - 128 REAR AXLE - 286RBIBR/BE
DIFFERENTIAL (Continued)

BRAKES
TABLE OF CONTENTS
page page
BRAKES - BASE........................... 1BRAKES - ABS........................... 35
BRAKES - BASE
TABLE OF CONTENTS
page page
BRAKES - BASE
SPECIFICATIONS
BASE BRAKE.........................2
TORQUE CHART......................3
SPECIAL TOOLS
BASE BRAKES........................4
HYDRAULIC/MECHANICAL
DESCRIPTION..........................4
WARNING.............................4
DIAGNOSIS AND TESTING - BASE BRAKE
SYSTEM.............................5
STANDARD PROCEDURE
STANDARD PROCEDURE - MANUAL
BLEEDING............................7
STANDARD PROCEDURE - PRESSURE
BLEEDING............................8
BRAKE LINES
STANDARD PROCEDURE
STANDARD PROCEDURE - DOUBLE
INVERTED FLARING....................8
STANDARD PROCEDURE - ISO FLARING . . . 8
COMBINATION VALVE
DESCRIPTION..........................8
OPERATION............................9
DIAGNOSIS AND TESTING - COMBINATION
VALVE ...............................9
REMOVAL.............................9
INSTALLATION..........................9
DISC BRAKE CALIPERS
DESCRIPTION.........................10
OPERATION...........................10
REMOVAL
REMOVAL - REAR.....................10
REMOVAL - FRONT....................11
DISASSEMBLY.........................11
CLEANING............................12
INSPECTION..........................12ASSEMBLY............................13
INSTALLATION
INSTALLATION - REAR.................14
INSTALLATION - FRONT................14
FLUID
DIAGNOSIS AND TESTING - BRAKE FLUID
CONTAMINATION.....................15
STANDARD PROCEDURE - BRAKE FLUID
LEVEL..............................15
SPECIFICATIONS
BRAKE FLUID........................15
FLUID RESERVOIR
REMOVAL.............................15
INSTALLATION.........................15
PEDAL
DESCRIPTION.........................17
OPERATION...........................17
REMOVAL.............................17
INSTALLATION.........................17
POWER BRAKE BOOSTER
DIAGNOSIS AND TESTING - HYDRAULIC
BOOSTER...........................18
STANDARD PROCEDURE - BLEEDING......19
REMOVAL.............................19
INSTALLATION.........................19
ROTORS
DIAGNOSIS AND TESTING
DISC BRAKE ROTOR..................20
REMOVAL
REMOVAL - REAR.....................21
REMOVAL - FRONT ± 2500..............22
REMOVAL - FRONT - 3500..............22
INSTALLATION
INSTALLATION - REAR.................22
INSTALLATION - FRONT ± 2500..........23
INSTALLATION - FRONT - 3500...........23
BR/BEBRAKES 5 - 1

BRAKE PADS/SHOES
REMOVAL
REMOVAL - REAR.....................23
REMOVAL - FRONT....................24
INSTALLATION
INSTALLATION - REAR.................25
INSTALLATION - FRONT................26
MASTER CYLINDER
DESCRIPTION.........................26
OPERATION...........................26
DIAGNOSIS AND TESTING - MASTER
CYLINDER/POWER BOOSTER...........26
STANDARD PROCEDURE - MASTER
CYLINDER BLEEDING..................27
REMOVAL.............................27
INSTALLATION.........................28
PARKING BRAKE
DESCRIPTION.........................28
OPERATION...........................28
PEDAL
REMOVAL.............................28
INSTALLATION.........................29CABLES
REMOVAL
REMOVAL - REAR PARK BRAKE CABLE . . . 29
REMOVAL - FRONT PARKING BRAKE
CABLE..............................29
INSTALLATION
INSTALLATION - REAR PARK BRAKE
CABLE..............................30
INSTALLATION - FRONT PARKING BRAKE
CABLE..............................30
CABLE TENSIONER
ADJUSTMENTS
ADJUSTMENT........................30
RELEASE HANDLE
REMOVAL.............................31
INSTALLATION.........................32
SHOES
REMOVAL.............................32
INSTALLATION.........................32
ADJUSTMENTS
ADJUSTMENT - PARKING BRAKE SHOES . . 33
BRAKES - BASE
SPECIFICATIONS
BASE BRAKE
SPECIFICATIONS
DESCRIPTION SPECIFICATION
Front/Rear Disc Brake
Caliper
TypeDual Piston Sliding
Front Disc Brake Caliper
Piston Diameter HD56 mm (2.00 in.)
Front Disc Brake Rotor 326.5ý36 mm
(12.5ý1.5 in.)
Front/Rear Disc Brake
Rotor
Max. Runout0.127 mm (0.005 in.)
Front/Rear Disc Brake
Rotor
Max. Thickness Variation0.025 mm (0.001 in.)
DESCRIPTION SPECIFICATION
Minimum Front Rotor
Thickness33.90 mm (1.334 in.)
Mininium Rear Rotor
Thickness28.39 mm (1.117 in)
Rear Disc Brake Caliper
25002x45 mm (1.77 in)
Rear Disc Brake Caliper
35002x51 mm (2.00 in)
Rear Disc Brake Rotor
2500/3500323.5x30 mm (1.18 in)
Brake Booster
Type
2500 Gasoline EnginesVacuum Dual Diaphragm
Brake Booster
Type
All 3500/
2500 Diesel Engines
OnlyHydraulic
5 - 2 BRAKES - BASEBR/BE

TORQUE CHART
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Booster
Mounting Nuts To
Dashpanel28 21 250
Master Cylinder
Mounting Nuts23 17 200
Master Cylinder
Brake Lines21 16 190
Combination Valve
Mounting Bolt23 17 210
Combination Valve
Brake Lines21 16 190
Proportioning Valve
Mounting Nuts34 25 300
Proportioning Valve
Brake Hose31 23 276
Proportioning Valve
Brake Lines21 16 190
Front Caliper
Mounting Bolts33 24 Ð
Front Caliper
HD Adapter Bolts285 210 Ð
Rear Caliper
Slide Pins33 24 300
Rotor to Hub Rear
Bolt128 95 Ð
All Caliper
Banjo Bolts40 30 360
Support Plate
Mounting Bolts58 43 Ð
Park Brake Pedal
Assembly
Mounting Bolts/Nuts28 21 250
Hub/Bearing
HD 4x2 Spindle Nut380 280 Ð
Hub/Bearing
4x4 Hub/Bearing Bolts170 125 Ð
BR/BEBRAKES - BASE 5 - 3
BRAKES - BASE (Continued)

SPECIAL TOOLS
BASE BRAKESHYDRAULIC/MECHANICAL
DESCRIPTION
This vehicle is equipped with front disc brakes and
rear drum brakes also certain vehicles have four
wheel disc brakes. The front and rear disc brakes
consist of dual piston calipers and ventilated rotors.
The rear brakes are dual brake shoe, internal
expanding units with cast brake drums. The parking
brake mechanism is cable operated and connected to
the rear brake trailing shoes. Power brake assist is
standard equipment. A vacuum operated power brake
booster is used on gas engine vehicles. A hydraulic
booster is used on diesel engine vehicles.
Two antilock brake systems are used on this vehi-
cle. A rear wheel antilock (RWAL) brake system and
all-wheel antilock brake system (ABS). The RWAL
and ABS systems are designed to retard wheel
lockup while braking. Retarding wheel lockup is
accomplished by modulating fluid pressure to the
wheel brake units. Both systems are monitored by a
microprocessor which controls the operation of the
systems.
WARNING
WARNING: DUST AND DIRT ACCUMULATING ON
BRAKE PARTS DURING NORMAL USE MAY CON-
TAIN ASBESTOS FIBERS FROM PRODUCTION OR
AFTERMARKET LININGS. BREATHING EXCESSIVE
CONCENTRATIONS OF ASBESTOS FIBERS CAN
CAUSE SERIOUS BODILY HARM. EXERCISE CARE
WHEN SERVICING BRAKE PARTS. DO NOT CLEAN
BRAKE PARTS WITH COMPRESSED AIR OR BY
DRY BRUSHING. USE A VACUUM CLEANER SPE-
CIFICALLY DESIGNED FOR THE REMOVAL OF
ASBESTOS FIBERS FROM BRAKE COMPONENTS.
IF A SUITABLE VACUUM CLEANER IS NOT AVAIL-
ABLE, CLEANING SHOULD BE DONE WITH A
WATER DAMPENED CLOTH. DO NOT SAND, OR
GRIND BRAKE LINING UNLESS EQUIPMENT USED
IS DESIGNED TO CONTAIN THE DUST RESIDUE.
DISPOSE OF ALL RESIDUE CONTAINING ASBES-
TOS FIBERS IN SEALED BAGS OR CONTAINERS
TO MINIMIZE EXPOSURE TO YOURSELF AND OTH-
ERS. FOLLOW PRACTICES PRESCRIBED BY THE
OCCUPATIONAL SAFETY AND HEALTH ADMINIS-
TRATION AND THE ENVIRONMENTAL PROTECTION
AGENCY FOR THE HANDLING, PROCESSING, AND
DISPOSITION OF DUST OR DEBRIS THAT MAY
CONTAIN ASBESTOS FIBERS.
Installer, Brake Caliper Dust Boot C-4340
Installer, Brake Caliper Dust Boot C-3716-A
Handle C-4171
Cap, Master Cylinder Pressure Bleed 6921
5 - 4 BRAKES - BASEBR/BE
BRAKES - BASE (Continued)

CAUTION: Never use gasoline, kerosene, alcohol,
motor oil, transmission fluid, or any fluid containing
mineral oil to clean the system components. These
fluids damage rubber cups and seals. Use only
fresh brake fluid or Mopar brake cleaner to clean or
flush brake system components. These are the only
cleaning materials recommended. If system contam-
ination is suspected, check the fluid for dirt, discol-
oration, or separation into distinct layers. Also
check the reservoir cap seal for distortion. Drain
and flush the system with new brake fluid if con-
tamination is suspected.
CAUTION: Use Mopar brake fluid, or an equivalent
quality fluid meeting SAE/DOT standards J1703 and
DOT 3. Brake fluid must be clean and free of con-
taminants. Use fresh fluid from sealed containers
only to ensure proper antilock component opera-
tion.
CAUTION: Use Mopar multi-mileage or high temper-
ature grease to lubricate caliper slide surfaces,
drum brake pivot pins, and shoe contact points on
the backing plates. Use multi-mileage grease or GE
661 or Dow 111 silicone grease on caliper slide pins
to ensure proper operation.
DIAGNOSIS AND TESTING - BASE BRAKE
SYSTEM
Base brake components consist of the brake shoes,
calipers, wheel cylinders, brake drums, rotors, brake
lines, master cylinder, booster, and parking brake
components.
Brake diagnosis involves determining if the prob-
lem is related to a mechanical, hydraulic, or vacuum
operated component.
The first diagnosis step is the preliminary check.
PRELIMINARY BRAKE CHECK
(1) Check condition of tires and wheels. Damaged
wheels and worn, damaged, or underinflated tires
can cause pull, shudder, vibration, and a condition
similar to grab.
(2) If complaint was based on noise when braking,
check suspension components. Jounce front and rear
of vehicle and listen for noise that might be caused
by loose, worn or damaged suspension or steering
components.
(3) Inspect brake fluid level and condition. Note
that the brake reservoir fluid level will decrease in
proportion to normal lining wear.Also note that
brake fluid tends to darken over time. This is
normal and should not be mistaken for contam-
ination.(a) If fluid level is abnormally low, look for evi-
dence of leaks at calipers, wheel cylinders, brake
lines, and master cylinder.
(b) If fluid appears contaminated, drain out a
sample to examine. System will have to be flushed
if fluid is separated into layers, or contains a sub-
stance other than brake fluid. The system seals
and cups will also have to be replaced after flush-
ing. Use clean brake fluid to flush the system.
(4) Check parking brake operation. Verify free
movement and full release of cables and pedal. Also
note if vehicle was being operated with parking
brake partially applied.
(5) Check brake pedal operation. Verify that pedal
does not bind and has adequate free play. If pedal
lacks free play, check pedal and power booster for
being loose or for bind condition. Do not road test
until condition is corrected.
(6) Check booster vacuum check valve and hose.
(7) If components checked appear OK, road test
the vehicle.
ROAD TESTING
(1) If complaint involved low brake pedal, pump
pedal and note if it comes back up to normal height.
(2) Check brake pedal response with transmission
in Neutral and engine running. Pedal should remain
firm under constant foot pressure.
(3) During road test, make normal and firm brake
stops in 25-40 mph range. Note faulty brake opera-
tion such as low pedal, hard pedal, fade, pedal pulsa-
tion, pull, grab, drag, noise, etc.
(4) Attempt to stop the vehicle with the parking
brake only and note grab, drag, noise, etc.
PEDAL FALLS AWAY
A brake pedal that falls away under steady foot
pressure is generally the result of a system leak. The
leak point could be at a brake line, fitting, hose, or
caliper/wheel cylinder. If leakage is severe, fluid will
be evident at or around the leaking component.
Internal leakage (seal by-pass) in the master cylin-
der caused by worn or damaged piston cups, may
also be the problem cause.
An internal leak in the ABS or RWAL system may
also be the problem with no physical evidence.
LOW PEDAL
If a low pedal is experienced, pump the pedal sev-
eral times. If the pedal comes back up, worn linings,
rotors, drums, or rear brakes out of adjustment are
the most likely causes. The proper course of action is
to inspect and replace all worn component and make
the proper adjustments.
BR/BEBRAKES - BASE 5 - 5
HYDRAULIC/MECHANICAL (Continued)

SPONGY PEDAL
A spongy pedal is most often caused by air in the
system. However, thin brake drums or substandard
brake lines and hoses can also cause a spongy pedal.
The proper course of action is to bleed the system,
and replace thin drums and substandard quality
brake hoses if suspected.
HARD PEDAL OR HIGH PEDAL EFFORT
A hard pedal or high pedal effort may be due to
lining that is water soaked, contaminated, glazed, or
badly worn. The power booster or check valve could
also be faulty.
PEDAL PULSATION
Pedal pulsation is caused by components that are
loose, or beyond tolerance limits.
The primary cause of pulsation are disc brake
rotors with excessive lateral runout or thickness vari-
ation, or out of round brake drums. Other causes are
loose wheel bearings or calipers and worn or dam-
aged tires.
NOTE: Some pedal pulsation may be felt during
ABS/EBD activation.
BRAKE DRAG
Brake drag occurs when the lining is in constant
contact with the rotor or drum. Drag can occur at one
wheel, all wheels, fronts only, or rears only.
Drag is a product of incomplete brake shoe release.
Drag can be minor or severe enough to overheat the
linings, rotors and drums.
Minor drag will usually cause slight surface char-
ring of the lining. It can also generate hard spots in
rotors and drums from the overheat-cool down pro-
cess. In most cases, the rotors, drums, wheels and
tires are quite warm to the touch after the vehicle is
stopped.
Severe drag can char the brake lining all the way
through. It can also distort and score rotors and
drums to the point of replacement. The wheels, tires
and brake components will be extremely hot. In
severe cases, the lining may generate smoke as it
chars from overheating.
Common causes of brake drag are:
²Seized or improperly adjusted parking brake
cables
²Loose/worn wheel bearing
²Seized caliper or wheel cylinder piston
²Caliper binding on damaged or missing anti-rat-
tle clips or bushings
²Loose caliper mounting
²Drum brake shoes binding on worn/damaged
support plates
²Mis-assembled components²Long booster output rod
If brake drag occurs at all wheels, the problem
may be related to a blocked master cylinder return
port, or faulty power booster (binds-does not release).
BRAKE FADE
Brake fade is usually a product of overheating
caused by brake drag. However, brake overheating
and resulting fade can also be caused by riding the
brake pedal, making repeated high deceleration stops
in a short time span, or constant braking on steep
mountain roads. Refer to the Brake Drag information
in this section for causes.
BRAKE PULL
Front brake pull condition could result from:
²Contaminated lining in one caliper
²Seized caliper piston
²Binding caliper
²Loose caliper
²Damaged anti-rattle clips
²Improper brake shoes
²Damaged rotor
A worn, damaged wheel bearing or suspension
component are further causes of pull. A damaged
front tire (bruised, ply separation) can also cause
pull.
A common and frequently misdiagnosed pull condi-
tion is where direction of pull changes after a few
stops. The cause is a combination of brake drag fol-
lowed by fade at one of the brake units.
As the dragging brake overheats, efficiency is so
reduced that fade occurs. Since the opposite brake
unit is still functioning normally, its braking effect is
magnified. This causes pull to switch direction in
favor of the normally functioning brake unit.
An additional point when diagnosing a change in
pull condition concerns brake cool down. Remember
that pull will return to the original direction, if the
dragging brake unit is allowed to cool down (and is
not seriously damaged).
REAR BRAKE GRAB OR PULL
Rear grab or pull is usually caused by improperly
adjusted or seized parking brake cables, contami-
nated lining, bent or binding shoes and support
plates, or improperly assembled components. This is
particularly true when only one rear wheel is
involved. However, when both rear wheels are
affected, the master cylinder or proportioning valve
could be at fault.
BRAKES DO NOT HOLD AFTER DRIVING THROUGH DEEP
WATER PUDDLES
This condition is generally caused by water soaked
lining. If the lining is only wet, it can be dried by
driving with the brakes very lightly applied for a
5 - 6 BRAKES - BASEBR/BE
HYDRAULIC/MECHANICAL (Continued)