brake DODGE RAM 2002 Service Workshop Manual

PEDAL
DESCRIPTION
The brake booster is operated by a suspended type
brake pedal. The pedal pivots on a shaft located in a
mounting bracket attached to the dash panel. The
pedal shaft is supported by bushings in the pedal
and mounting bracket. The brake pedal is attached
to the booster push rod.
OPERATION
When the pedal is depressed, the primary booster
push rod is depressed which move the booster sec-
ondary rod. The booster secondary rod depress the
master cylinder piston.
REMOVAL
(1) Remove knee bolster, (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - REMOVAL).
(2) Remove brake lamp switch, (Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/BRAKE
LAMP SWITCH - REMOVAL).
(3) Remove switches from tabs on brake lamp
switch bracket.
(4) Remove brake lamp switch bracket bolts and
remove bracket (Fig. 25).
(5) Remove clip and washer attaching booster push
rod and slide push rod off pedal.
(6) Remove E-clip from passenger side of pedal
shaft (Fig. 26). Use flat blade screwdriver to pry clip
out of shaft groove.
(7) Push shaft toward driver side of bracket just
enough to expose opposite E-clip. Then remove E-clip
with flat blade screwdriver.(8) Push pedal shaft back and out of passenger
side of bracket (Fig. 26).
(9) Remove pedal shaft, brake pedal, wave washer
and bushings from vehicle.
INSTALLATION
(1) Replace bracket and pedal bushings if neces-
sary. Lubricate shaft bores in bracket and pedal
before installing bushings with Mopar Multi-mileage
silicone grease.
(2) Apply liberal quantity of Mopar multi-mileage
grease to pedal shaft and to pedal and bracket bush-
ings.
(3) Position brake pedal in mounting bracket.
(4) Slide pedal shaft into bracket and through
pedal from passenger side.
(5) Push pedal shaft out driver side of mounting
bracket just enough to allow installation of retaining
E-clip.
(6) Install the wave washer between the bracket
and the pedal bushing on the passenger side.
(7) Push pedal shaft back toward passenger side of
bracket and install remaining E-clip on pedal shaft.
(8) Install booster push rod on brake pedal. Secure
push rod to pedal with washer and retaining clip.
(9) Install brake lamp switch bracket and switch,
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
Fig. 25 Brake Lamp Switch Bracket
1 - PEDAL BRACKET
2 - BRAKELIGHT SWITCH BRACKET
3 - BRACKET SCREWS (2)
Fig. 26 Brake Pedal Mounting (With Automatic
Transmission)
1 - PEDAL SHAFT
2 - SHAFT RETAINING E-CLIPS (2)
3 - BRAKE PEDAL
4 - PEDAL BUSHING (2)
5 - PEDAL MOUNTING BRACKET
BR/BEBRAKES - BASE 5 - 17

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)

(7) Install the hydraulic booster pressure lines to
the bracket and booster.
(8) Tighten the pressure lines to 41 N´m (30 ft.
lbs.).
NOTE: Inspect o-rings on the pressure line fittings
to insure they are in good condition before installa-
tion. Replace o-rings if necessary.
(9) Install the return hose to the booster.(10) Bleed base brake system, (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL - STAN-
DARD PROCEDURE).
(11) Fill the power steering pump with fluid,
(Refer to 19 - STEERING/PUMP - STANDARD PRO-
CEDURE).
CAUTION: Use only MOPAR power steering fluid or
equivalent. Do not use automatic transmission fluid
and do not overfill.
(12) Bleed the hydraulic booster.
ROTORS
DIAGNOSIS AND TESTING
DISC BRAKE ROTOR
The rotor braking surfaces should not be refinished
unless necessary.
Light surface rust and scale can be removed with a
lathe equipped with dual sanding discs. The rotor
surfaces can be restored by machining with a disc
brake lathe if surface scoring and wear are light.
Replace the rotor for the following conditions:
²Severely Scored
²Tapered
²Hard Spots
²Cracked
²Below Minimum Thickness
Fig. 28 Master Cylinder And Booster
1 - MASTER CYLINDER
2 - RETURN LINE
3 - LINE FROM PUMP
4 - HYDRAULIC BOOSTER
5 - LINE TO GEAR
Fig. 29 Booster Push Rod
1 - BOOSTER PUSH ROD
2 - WASHER
3 - CLIP
4 - PEDAL
Fig. 30 Booster Mounting
1 - STEERING COLUMN
2 - MOUNTING NUTS
3 - BOOSTER PEDAL ROD
4 - MOUNTING NUTS
5 - 20 BRAKES - BASEBR/BE
POWER BRAKE BOOSTER (Continued)

ROTOR MINIMUM THICKNESS
Measure rotor thickness at the center of the brake
shoe contact surface. Replace the rotor if below min-
imum thickness, or if machining would reduce thick-
ness below the allowable minimum.
Rotor minimum thickness is usually specified on
the rotor hub. The specification is either stamped or
cast into the hub surface.
ROTOR RUNOUT
Check rotor lateral runout with dial indicator
C-3339 (Fig. 31) . Excessive lateral runout will cause
brake pedal pulsation and rapid, uneven wear of the
brake shoes. Position the dial indicator plunger
approximately 25.4 mm (1 in.) inward from the rotor
edge.
NOTE: Be sure wheel bearing has zero end play
before checking rotor runout.
Maximum allowable rotor runout is 0.127 mm
(0.005 in.).
ROTOR THICKNESS VARIATION
Variations in rotor thickness will cause pedal pul-
sation, noise and shudder.
Measure rotor thickness at 6 to 12 points around
the rotor face (Fig. 32) .
Position the micrometer approximately 25.4 mm (1
in.) from the rotor outer circumference for each mea-
surement.
Thickness should notvaryby more than 0.025 mm
(0.001 in.) from point-to-point on the rotor. Machine
or replace the rotor if necessary.
REMOVAL
REMOVAL - REAR
(1) Raise and support the vehicle
(2) Remove the tire and wheel assembly.
(3) Remove the disc brake caliper, (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPERS - REMOVAL).
(4) Remove the caliper adapter bolts.
(5) Remove the rear axle shaft from the housing
on dual rear wheels, (Refer to 3 - DIFFERENTIAL &
DRIVELINE/REAR AXLE - 286RBI/AXLE SHAFTS -
REMOVAL).
(6) Remove the hub and rotor assembly (C3500
only) (Fig. 33).
Fig. 31 Checking Rotor Runout And Thickness
Variation
1 - DIAL INDICATOR
Fig. 32 Measuring Rotor Thickness
1 - MICROMETER
2 - ROTOR
Fig. 33 ROTOR / HUB REMOVAL
BR/BEBRAKES - BASE 5 - 21
ROTORS (Continued)

REMOVAL - FRONT ± 2500
(1) Raise and support the vehicle.
(2) Remove the wheel and tire assembly.
(3) Remove the caliper from the steering knuckle,
(Refer to 5 - BRAKES/HYDRAULIC/MECHANICAL/
DISC BRAKE CALIPERS - REMOVAL) and remove
caliper adapter assembly (Fig. 34).
NOTE: Do not allow brake hose to support caliper
adapter assembly.
(4) Remove the rotor from the hub/bearing wheel
studs.
REMOVAL - FRONT - 3500
(1) Raise and support the vehicle.
(2) Remove the wheel and tire assembly.
(3) Remove the hub extension mounting nuts and
remove the extension from the rotor if equipped.
(4) Remove the brake caliper adapter assembly.
(Refer to 5 - BRAKES/HYDRAULIC/MECHANICAL/
DISC BRAKE CALIPERS - REMOVAL).
(5) Remove the rotor assembly.
INSTALLATION
INSTALLATION - REAR
(1) Install the hub to the rotor. Tighten the bolts to
128 N´m (95 ft. lbs.) (Fig. 35).
(2) Install the hub and rotor assembly.
(3) Install the rear axle shaft to the housing with
dual wheels, (Refer to 3 - DIFFERENTIAL & DRIV-
ELINE/REAR AXLE - 286RBI/AXLE SHAFTS -
INSTALLATION).
(4) Install the caliper adapter bolts.
(5) Install the disc brake caliper, (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPERS - INSTALLATION). (Fig. 36).
(6) Install the tire and wheel assembly, (Refer to
22 - TIRES/WHEELS/WHEELS - STANDARD PRO-
CEDURE).
(7) Lower the vehicle.
Fig. 34 Caliper Adapter Assembly
1 - KNUCKLE
2 - CALIPER
3 - ROTOR
Fig. 35 ROTOR TO HUB
1 - Hub Bolts
2 - Socket
Fig. 36 ROTOR INSTALLED
5 - 22 BRAKES - BASEBR/BE
ROTORS (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)

REMOVAL - FRONT
(1) Raise and support vehicle.
(2) Remove front wheel and tire assemblies.
(3) Compress caliper.
(4) Remove caliper, (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/DISC BRAKE CALIPERS
- REMOVAL).
(5) Remove caliper by tilting the top up and off the
caliper adapter (Fig. 42).NOTE: Do not allow brake hose to support caliper
assembly.
(6) Remove inboard brake shoe from the caliper
adapter (Fig. 43).
(7) Remove outboard brake shoe from caliper
adapter (Fig. 44).
(8) Remove the anti-rattle springs from the caliper
adapter (Fig. 45) and (Fig. 46).
NOTE: Anti-rattle springs are not interchangeable.
Fig. 39 Outboard Brake Shoe
1 - OUTBOARD SHOE
2 - CALIPER ADAPTER
Fig. 40 Top Anti-Rattle Spring
1 - CALIPER ADAPTER
2 - ANTI-RATTLE SPRING
Fig. 41 Bottom Anti-Rattle Spring
1 - ANTI-RATTLE SPRING
2 - CALIPER ADAPTER
Fig. 42 Caliper
1 - CALIPER
2 - CALIPER ADAPTER
5 - 24 BRAKES - BASEBR/BE
BRAKE PADS/SHOES (Continued)

INSTALLATION
INSTALLATION - REAR
(1) Clean caliper mounting adapter and anti-rattle
springs.
(2) Lubricate anti-rattle springs with Mopar brake
grease.
(3) Install anti-rattle springs.
NOTE: Anti-rattle springs are not interchangeable.
(4) Install inboard brake shoe in adapter.
(5) Install outboard brake shoe in adapter.
(6) Tilt the bottom of the caliper over rotor and
under adapter. Then push the top of the caliper down
onto the adapter.
Fig. 43 Inboard Brake Shoe
1 - INBOARD SHOE
2 - CALIPER ADAPTER
Fig. 44 Outboard Brake Shoe
1 - OUTBOARD SHOE
2 - CALIPER ADAPTER
Fig. 45 Top Anti-Rattle Spring
1 - CALIPER ADAPTER
2 - ANTI-RATTLE SPRING
Fig. 46 Bottom Anti-Rattle Spring
1 - ANTI-RATTLE SPRING
2 - CALIPER ADAPTER
BR/BEBRAKES - BASE 5 - 25
BRAKE PADS/SHOES (Continued)

(7) Install caliper, (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/DISC BRAKE CALIPERS
- INSTALLATION) (Refer to 5 - BRAKES/HYDRAU-
LIC/MECHANICAL/DISC BRAKE CALIPERS -
INSTALLATION).
(8) Install wheel and tire assemblies and lower
vehicle, (Refer to 22 - TIRES/WHEELS/WHEELS -
STANDARD PROCEDURE).
(9) Apply brakes several times to seat caliper pis-
tons and brake shoes and obtain firm pedal.
(10) Top off master cylinder fluid level.
INSTALLATION - FRONT
(1) Bottom pistons in caliper bore with C-clamp.
Place an old brake shoe between a C-clamp and cal-
iper piston.
(2) Clean caliper mounting adapter and anti-rattle
springs.
(3) Lubricate anti-rattle springs with Mopar brake
grease.
(4) Install anti-rattle springs.
NOTE: Anti-rattle springs are not interchangeable.
(5) Install inboard brake shoe in adapter.
(6) Install outboard brake shoe in adapter.
(7) Tilt the bottom of the caliper over rotor and
under adapter. Then push the top of the caliper down
onto the adapter.
(8) Install caliper, (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/DISC BRAKE CALIPERS
- INSTALLATION).
(9) Install wheel and tire assemblies and lower
vehicle, (Refer to 22 - TIRES/WHEELS/WHEELS -
STANDARD PROCEDURE).
(10) Apply brakes several times to seat caliper pis-
tons and brake shoes and obtain firm pedal.
(11) Top off master cylinder fluid level.
MASTER CYLINDER
DESCRIPTION
A two-piece master cylinder is used on all models.
The cylinder body containing the primary and sec-
ondary pistons is made of aluminum. The removable
fluid reservoir is made of nylon reinforced with glass
fiber. The reservoir stores reserve brake fluid for the
hydraulic brake circuits. The reservoir is the only
serviceable component.
The fluid compartments of the nylon reservoir are
interconnected to permit fluid level equalization.
However, the equalization feature does not affect cir-
cuit separation in the event of a front or rear brake
malfunction. The reservoir compartments will retain
enough fluid to operate the functioning hydraulic cir-
cuit.Care must be exercised when removing/installing
the master cylinder connecting lines. The threads in
the cylinder fluid ports can be damaged if care is not
exercised. Start all brake line fittings by hand to
avoid cross threading.
The cylinder reservoir can be replaced when neces-
sary. However, the aluminum body section of the
master cylinder is not a repairable component.
NOTE: If diagnosis indicates that an internal mal-
function has occurred, the aluminum body section
must be replaced as an assembly.
OPERATION
The master cylinder bore contains a primary and
secondary piston. The primary piston supplies
hydraulic pressure to the front brakes. The secondary
piston supplies hydraulic pressure to the rear brakes.
DIAGNOSIS AND TESTING - MASTER
CYLINDER/POWER BOOSTER
(1) Start engine and check booster vacuum hose
connections. A hissing noise indicates vacuum leak.
Correct any vacuum leak before proceeding.
(2) Stop engine and shift transmission into Neu-
tral.
(3) Pump brake pedal until all vacuum reserve in
booster is depleted.
(4) Press and hold brake pedal under light foot
pressure. The pedal should hold firm, if the pedal
falls away master cylinder is faulty (internal leak-
age).
(5) Start engine and note pedal action. It should
fall away slightly under light foot pressure then hold
firm. If no pedal action is discernible, power booster,
vacuum supply, or vacuum check valve is faulty. Pro-
ceed to the POWER BOOSTER VACUUM TEST.
(6) If the POWER BOOSTER VACUUM TEST
passes, rebuild booster vacuum reserve as follows:
Release brake pedal. Increase engine speed to 1500
rpm, close the throttle and immediately turn off igni-
tion to stop engine.
(7) Wait a minimum of 90 seconds and try brake
action again. Booster should provide two or more vac-
uum assisted pedal applications. If vacuum assist is
not provided, booster is faulty.
POWER BOOSTER VACUUM TEST
(1) Connect vacuum gauge to booster check valve
with short length of hose and T-fitting (Fig. 47).
(2) Start and run engine at curb idle speed for one
minute.
(3) Observe the vacuum supply. If vacuum supply
is not adequate, repair vacuum supply.
5 - 26 BRAKES - BASEBR/BE
BRAKE PADS/SHOES (Continued)