2002 DODGE RAM lock

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)

REMOVAL - FRONT
(1) Raise and support vehicle.
(2) Remove front wheel and tire assembly.
(3) Remove caliper brake hose bolt, washers and
hose (Fig. 8).
(4) Remove caliper mounting bolts.
(5) Tilt the top of the caliper up and remove it
from the adapter.
(6) Remove anti-rattle springs.
NOTE: Upper and lower anti-rattle springs are not
interchangeable.
DISASSEMBLY
(1) Drain the brake fluid from caliper.
(2) C-clamp a block of wood over one piston (Fig.
9).
(3) Take another piece of wood and pad it with
one-inch thickness of shop towels. Place this piece in
the outboard shoe side of the caliper in front of the
other piston. This will cushion and protect caliper
piston during removal (Fig. 10).
(4) To remove the caliper piston directshort
bursts of low pressure airwith a blow gun
through the caliper brake hose port. Use only enough
air pressure to ease the piston out.
Fig. 6 Lining Wear Compensation By Piston Seal
1 - PISTON
2 - CYLINDER BORE
3 - PISTON SEAL BRAKE PRESSURE OFF
4 - CALIPER HOUSING
5 - DUST BOOT
6 - PISTON SEAL BRAKE PRESSURE ON
Fig. 7 REAR CALIPER
1 - Banjo Bolt
2 - Caliper Pin Bolts
Fig. 8 Caliper
1 - WASHERS
2 - MOUNTING BOLTS
3 - HOSE BOLT
Fig. 9 C-Clamp One Piston
1 - BLOCK OF WOOD
2 - C-CLAMP
3 - CALIPER
BR/BEBRAKES - BASE 5 - 11
DISC BRAKE CALIPERS (Continued)

CAUTION: Do not blow the piston out of the bore
with sustained air pressure. This could result in a
cracked piston.
WARNING: NEVER ATTEMPT TO CATCH THE PIS-
TON AS IT LEAVES THE BORE. THIS COULD
RESULT IN PERSONAL INJURY.
(5) Remove the C-clamp and block of wood from
the caliper and clamp it over the dust boot of the
first piston removed. This will seal the empty piston
bore.
(6) Move the padded piece of wood in front of the
other piston.
(7) Remove the second piston using the same pro-
cedure withshort bursts of low pressure air.
(8) Remove piston dust boots with a suitable pry
tool (Fig. 11).
(9) Remove piston seals from caliper (Fig. 12).
CAUTION: Do not scratch piston bore while remov-
ing the seals.
(10) Push caliper mounting bolt bushings out of
the boot seals and remove the boot seals from the
caliper (Fig. 13).
(11) Remove caliper bleed screw.
CLEANING
Clean the caliper components with clean brake
fluid or brake clean only. Wipe the caliper and piston
dry with lint free towels or use low pressure com-
pressed air.CAUTION: Do not use gasoline, kerosene, thinner,
or similar solvents. These products may leave a
residue that could damage the piston and seal.
INSPECTION
The piston is made from a phenolic resin (plastic
material) and should be smooth and clean.
The piston must be replaced if cracked or scored.
Do not attempt to restore a scored piston surface by
sanding or polishing.
Fig. 10 Protect Caliper Piston
1 - CALIPER
2 - PADDED BLOCK OF WOOD
3 - C-CLAMP
Fig. 11 Piston Dust Boot Removal
1 - CALIPER
2 - DUST BOOT
Fig. 12 Piston Seal
1 - CALIPER
2 - PISTON BORE
3 - PISTON SEAL
5 - 12 BRAKES - BASEBR/BE
DISC BRAKE CALIPERS (Continued)

(8) Remove the supports and lower the vehicle.
(9) Verify a firm pedal before moving the vehicle.
FLUID
DIAGNOSIS AND TESTING - BRAKE FLUID
CONTAMINATION
Indications of fluid contamination are swollen or
deteriorated rubber parts.
Swollen rubber parts indicate the presence of
petroleum in the brake fluid.
To test for contamination, put a small amount of
drained brake fluid in clear glass jar. If fluid sepa-
rates into layers, there is mineral oil or other fluid
contamination of the brake fluid.
If brake fluid is contaminated, drain and thor-
oughly flush system. Replace master cylinder, propor-
tioning valve, caliper seals, wheel cylinder seals,
Antilock Brakes hydraulic unit and all hydraulic
fluid hoses.
STANDARD PROCEDURE - BRAKE FLUID
LEVEL
Always clean the master cylinder reservoir and
caps before checking fluid level. If not cleaned, dirt
could enter the fluid.
The fluid fill level is indicated on the side of the
master cylinder reservoir (Fig. 19).
The correct fluid level is to the FULL indicator on
the side of the reservoir. If necessary, add fluid to the
proper level.
SPECIFICATIONS
BRAKE FLUID
The brake fluid used in this vehicle must conform
to DOT 3 specifications and SAE J1703 standards.
No other type of brake fluid is recommended or
approved for usage in the vehicle brake system. Use
only Mopar brake fluid or an equivalent from a
tightly sealed container.
CAUTION: Never use reclaimed brake fluid or fluid
from an container which has been left open. An
open container of brake fluid will absorb moisture
from the air and contaminate the fluid.
CAUTION: Never use any type of a petroleum-based
fluid in the brake hydraulic system. Use of such
type fluids will result in seal damage of the vehicle
brake hydraulic system causing a failure of the
vehicle brake system. Petroleum based fluids would
be items such as engine oil, transmission fluid,
power steering fluid, etc.
FLUID RESERVOIR
REMOVAL
(1) Remove reservoir cap and empty fluid into
drain container.
(2) Clamp cylinder body in vise with brass protec-
tive jaws.
(3) Remove pins that retain reservoir to master
cylinder. Use hammer and pin punch to remove pins
(Fig. 20).
(4) Loosen reservoir from grommets with pry tool
(Fig. 21).
(5) Remove reservoir by rocking it to one side and
pulling free of grommets (Fig. 22).
(6) Remove old grommets from cylinder body (Fig.
23).
INSTALLATION
CAUTION: Do not use any type of tool to install the
grommets. Tools may cut, or tear the grommets cre-
ating a leak problem after installation. Install the
grommets using finger pressure only.
(1) Lubricate new grommets with clean brake fluid
and Install new grommets in cylinder body (Fig. 24).
Use finger pressure to install and seat grommets.
(2) Start reservoir in grommets. Then rock reser-
voir back and forth while pressing downward to seat
it in grommets.
Fig. 19 Master Cylinder Fluid Level - Typical
1 - INDICATOR
2 - RESERVOIR
BR/BEBRAKES - BASE 5 - 15
DISC BRAKE CALIPERS (Continued)

EXTERIOR/BRAKE LAMP SWITCH - INSTALLA-
TION).
(10) Install knee bolster, (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - INSTALLATION).
POWER BRAKE BOOSTER
DIAGNOSIS AND TESTING - HYDRAULIC
BOOSTER
The hydraulic booster uses hydraulic pressure from
the power steering pump. Before diagnosing a
booster problem, first verify the power steering pump
is operating properly. Perform the following checks.
²Check the power steering fluid level.
²Check the brake fluid level.
²Check all power steering hoses and lines for
leaks and restrictions.
²Check power steering pump pressure.
NOISES
The hydraulic booster unit will produce certain
characteristic booster noises. The noises may occur
when the brake pedal is used in a manner not asso-
ciated with normal braking or driving habits.
HISSING
A hissing noise may be noticed when above normal
brake pedal pressure is applied, 40 lbs. or above. The
noise will be more noticeable if the vehicle is not
moving. The noise will increase with the brake pedal
pressure and an increase of system operating temper-
ature.
CLUNK-CHATTER-CLICKING
A clunk-chatter-clicking may be noticed when the
brake pedal is released quickly, after above normal
brake pedal pressure is applied 50-100 lbs..
BOOSTER FUNCTION TEST
With the engine off depress the brake pedal several
times to discharge the accumulator. Then depress the
brake pedal using 40 lbs. of force and start the
engine. The brake pedal should fall and then push
back against your foot. This indicates the booster is
operating properly.
ACCUMULATOR LEAKDOWN
(1) Start the engine, apply the brakes and turn the
steering wheel from lock to lock. This will ensure the
accumulator is charged. Turn off the engine and let
the vehicle sit for one hour. After one hour there
should be at least two power assisted brake applica-
tion with the engine off. If the system does not retain
a charge the booster must be replaced.(2) With the engine off depress the brake pedal
several times to discharge the accumulator. Grasp
the accumulator and see if it wobbles or turns. If it
does the accumulator has lost a gas charge and the
booster must be replaced.
SEAL LEAKAGE
If the booster leaks from any of the seals the
booster assembly must be replaced (Fig. 27).
²INPUT ROD SEAL:Fluid leakage from rear
end of the booster.
²PISTON SEAL:Fluid leakage from vent at
front of booster.
²HOUSING SEAL:Fluid leakage between hous-
ing and housing cover.
²SPOOL VALVE SEAL:Fluid leakage near
spool plug.
²RETURN PORT FITTING SEAL:Fluid leak-
age from port fitting.
Fig. 27 Hydraulic Booster Seals
1 - PUMP
2 - GEAR
3 - INPUT SEAL
4 - HOUSING SEAL
5 - ACCUMULATOR SEAL
6 - PISTON SEAL
7 - SPOOL PLUG SEAL
8 - RETURN
5 - 18 BRAKES - BASEBR/BE
PEDAL (Continued)

HYDRAULIC BOOSTER DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
Slow Brake Pedal Return 1. Excessive seal friction in booster. 1. Replace booster.
2. Faulty spool valve action. 2. Replace booster.
3. Restriction in booster return hose. 3. Replace hose.
4. Damaged input rod. 4. Replace booster.
Excessive Brake Pedal
Effort.1. Internal or external seal leakage. 1. Replace booster.
2. Faulty steering pump. 2. Replace pump.
Brakes Self Apply 1. Dump valve faulty. 1. Replace booster.
2. Contamination in hydraulic
system.2. Flush hydraulic system and replace
booster.
3. Restriction in booster return hose. 3. Replace hose.
Booster Chatter, Pedal
Vibration1. Slipping pump belt. 1. Replace power steering belt.
2. Low pump fluid level. 2. Fill pump and check for leaks.
Grabbing Brakes 1. Low pump flow. 1. Test and repair/replace pump.
2. Faulty spool valve action. 2. Replace booster.
STANDARD PROCEDURE - BLEEDING
The hydraulic booster is generally self-bleeding,
this procedure will normally bleed the air from the
booster. Normal driving and operation of the unit will
remove any remaining trapped air.
(1) Fill power steering pump reservoir.
(2) Disconnect fuel shutdown relay and crank the
engine for several seconds, Refer to Fuel System for
relay location and WARNING.
(3) Check fluid level and add if necessary.
(4) Connect fuel shutdown relay and start the
engine.
(5) Turn the steering wheel slowly from lock to
lock twice.
(6) Stop the engine and discharge the accumulator
by depressing the brake pedal 5 times.
(7) Start the engine and turn the steering wheel
slowly from lock to lock twice.
(8) Turn off the engine and check fluid level and
add if necessary.
NOTE: If fluid foaming occurs, wait for foam to dis-
sipate and repeat steps 7 and 8.
REMOVAL
NOTE: If the booster is being replaced because the
power steering fluid is contaminated, flush the
power steering system before replacing the booster.(1) With engine off depress the brake pedal 5
times to discharge the accumulator.
(2) Remove brake lines from master cylinder.
(3) Remove mounting nuts from the master cylin-
der.
(4) Remove the bracket from the hydraulic booster
lines and master cylinder mounting studs.
(5) Remove the master cylinder.
(6) Remove the return hose and the two pressure
lines from the hydraulic booster (Fig. 28).
(7) Remove the booster push rod clip, washer and
rod remove from the brake pedal. (Fig. 29).
(8) Remove the mounting nuts from the hydraulic
booster and remove the booster (Fig. 30).
INSTALLATION
(1) Install the hydraulic booster and tighten the
mounting nuts to 28 N´m (21 ft. lbs.).
(2) Install the booster push rod, washer and clip
onto the brake pedal.
(3) Install the master cylinder on the mounting
studs. and tighten the mounting nuts to 23 N´m (17
ft. lbs.).
(4) Install the brake lines to the master cylinder
and tighten to 19-200 N´m (170-200 in. lbs.).
(5) Install the hydraulic booster line bracket onto
the master cylinder mounting studs.
(6) Install the master cylinder mounting nuts and
tighten to 23 N´m (17 ft. lbs.).
BR/BEBRAKES - BASE 5 - 19
POWER BRAKE BOOSTER (Continued)

INSTALLATION - FRONT ± 2500
(1) On models with all-wheel antilock system
(ABS), check condition of tone wheel on hub/bearing.
If teeth on wheel are damaged, hub/bearing assembly
will have to be replaced (tone wheel is not serviced
separately).
(2) Install rotor onto the hub/bearing wheel studs.
(3) Install the caliper adapter assembly,(Refer to 5
- BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPERS - INSTALLATION) and tighten
adapter bolts to:
²LD 1500: 176 N´m (130 ft lbs.)
²HD 2500: 285 N´m (210 ft lbs.)
(4) Install the wheel and tire assembly, (Refer to
22 - TIRES/WHEELS/WHEELS - STANDARD PRO-
CEDURE) and lower vehicle.
(5) Apply brakes several times to seat brake shoes.
Be sure to obtain firm pedal before moving vehicle.
INSTALLATION - FRONT - 3500
(1) Position the rotor on the hub/bearing.
(2) Install the brake caliper adapter assembly
(Refer to 5 - BRAKES/HYDRAULIC/MECHANICAL/
DISC BRAKE CALIPERS - INSTALLATION) and
tighten adapter bolts to 285 N´m (210 ft. lbs).
(3) Install the wheel and tire assemblies, (Refer to
22 - TIRES/WHEELS/WHEELS - STANDARD PRO-
CEDURE).
(4) Remove the support and lower the vehicle.
(5) Apply brakes several times to seat brake shoes
and caliper piston. Do not move vehicle until firm
brake pedal is obtained.
BRAKE PADS/SHOES
REMOVAL
REMOVAL - REAR
(1) Raise and support the vehicle.
(2) Remove the rear wheel and tire assemblies.
(3) Compress the caliper.
(4) Remove caliper mounting bolts
NOTE: Do not allow brake hose to support caliper
assembly.
(5) Remove the caliper, (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/DISC BRAKE CALIPERS
- REMOVAL) and then tilt the top up and off the cal-
iper adapter (Fig. 37).
(6) Remove inboard brake shoe from the caliper
adapter (Fig. 38).
(7) Remove outboard brake shoe from caliper
adapter (Fig. 39).(8) Remove the anti-rattle springs from the caliper
adapter (Fig. 40) and (Fig. 41).
NOTE: Anti-rattle springs are not interchangeable.
Fig. 37 ROTOR / PADS/ CALIPER
1 - ROTOR
2 - BRAKE SHOES
3 - DISC BRAKE CALIPER
Fig. 38 Inboard Brake Shoe
1 - INBOARD SHOE
2 - CALIPER ADAPTER
BR/BEBRAKES - BASE 5 - 23
ROTORS (Continued)

INSTALLATION
NOTE: If master cylinder is replaced, bleed cylinder
before installation.
(1) Install master cylinder on the booster mount-
ing studs.
(2) Install mounting nuts and tighten to 23 N´m
(17 ft. lbs.).
(3) Install brake lines and tighten to 19-23 N´m
(170-200 in. lbs.).
(4) Bleed base brake system, (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL - STAN-
DARD PROCEDURE)
PARKING BRAKE
DESCRIPTION
The parking brakes are operated by a system of
cables and levers attached to a primary and second-
ary shoe positioned within the drum section of the
rotor.
The drum-in-hat design utilizes an independent set
of shoes to park the vehicle (Fig. 51).
OPERATION
To apply the parking brake the pedal is depressed.
This creates tension in the cable which pulls forward
on the park brake lever. The lever pushes the park
brake shoes outward and into contact with the drum
section of the rotor. The contact of shoe to rotor parks
the vehicle.A torsion locking mechanism is used to hold the
pedal in an applied position. Parking brake release is
accomplished by the hand release.
A parking brake switch is mounted on the parking
brake lever and is actuated by movement of the
lever. The switch, which is in circuit with the red
warning light in the dash, will illuminate the warn-
ing light whenever the parking brake is applied.
Parking brake adjustment is controlled by a cable
tensioner mechanism. The cable tensioner, once
adjusted at the factory, should not need further
adjustment under normal circumstances. Adjustment
may be required if a new tensioner, or cables are
installed, or disconnected.
PEDAL
REMOVAL
(1) Release the parking brake.
(2) Raise the vehicle.
(3) Loosen the cable tensioner nut at the equalizer
to create slack in the front cable.
(4) Lower the vehicle.
(5) Remove the knee bolster, (Refer to 23 - BODY/
INSTRUMENT PANEL/STEERING COLUMN
OPENING COVER - REMOVAL).
(6) Disconnect the brake lamp wire from the
switch on the pedal assembly.
(7) Roll the carpet back, loosen the front cable
grommet from the floorpan and the cable retainer.
(8) Disengage the cable end connector (Fig. 52)
from the arm on the pedal assembly.
Fig. 50 Master Cylinder
1 - MOUNTING NUT
2 - MOUNTING NUT
3 - BRAKE LINES
4 - MASTER CYLINDER
Fig. 51 SHOES REMOVAL
1 - PARK BRAKE SHOES
2 - ADJUSTER
3 - RETURN SPRINGS
4 - SPLASH SHIELD
5 - HOLD DOWNS
5 - 28 BRAKES - BASEBR/BE
MASTER CYLINDER (Continued)