1998 DODGE RAM 1500 Rear brake

(3) Install parking brake cable in the brake lever.
(4) Install the park brake shoes (Refer to 5 -
BRAKES/PARKING BRAKE/SHOES - INSTALLA-
TION). (Fig. 66).
(5) Install axle shaft, (Refer to 3 - DIFFEREN-
TIAL & DRIVELINE/REAR AXLE - 9 1/4/AXLE
SHAFTS - INSTALLATION).
(6) Adjust brake shoes to drum with brake gauge
(Refer to 5 - BRAKES/PARKING BRAKE/SHOES -
ADJUSTMENTS).
(7) Install the rotor (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/ROTORS - INSTALLA-
TION).
(8) Install the caliper adapter (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPER ADAPTER - INSTALLATION).
(9) Install the caliper (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/DISC BRAKE CALIPERS
- INSTALLATION).
(10) Install wheel and tire assembly.
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. 41).
The correct fluid level is to the MAX 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) Install the prop rod on the brake pedal to keep
pressure on the brake system.
(2) Remove the reservoir cap and siphon fluid into
a drain container (Fig. 42).
(3) Remove the electrical connector from the fluid
level switch in the reservoir (Fig. 42).
(4) Remove the reservoir mounting bolt (Fig. 42).
Fig. 41 FLUID LEVEL TYPICAL
1 - FLUID RESERVOIR
2 - MAX LEVEL MARK
DRBRAKES - BASE 5 - 23
DISC BRAKE CALIPER ADAPTER MOUNT (Continued)

(5) Remove the reservoir from the master cylinder
by pulling upwards.
(6) Remove old grommets from cylinder body (Fig.
42).
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 the new grommets with clean brake
fluid and Install new grommets in cylinder body. Use
finger pressure to install and seat grommets.
(2) Start the reservoir in grommets. Then rock the
reservoir back and forth while pressing downward to
seat it into the grommets.
(3) Install the mounting bolt for the reservoir to
the master cylinder.
(4) Reconnect the electrical connector to the fluid
reservoir level switch.
(5) Remove the prop rod from the vehicle.
(6) Fill and bleed base brake system,(Refer to 5 -
BRAKES - STANDARD PROCEDURE).
BRAKE JUNCTION BLOCK
REMOVAL
(1) Remove the brake lines from the junction block
(Fig. 43).
(2) Remove the junction block mounting bolt and
remove the junction block from the bracket (Fig. 43).
INSTALLATION
(1) Position the junction block on the bracket and
install the mounting bolt. Tighten the mounting bolt
to 23 N´m (210 in. lbs.) (Fig. 43).
(2) Install the brake lines into the junction block
and tighten to 19-23 N´m (170-200 in. lbs.) (Fig. 43).
(3) Bleed the base brake system, (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL - STAN-
DARD PROCEDURE).
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 and has a switch for indicat-
ing low fluid levels. The reservoir is the only service-
able 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.
Fig. 42 FLUID RESERVOIR
1 - MASTER CYLINDER CAP
2 - FLUID RESERVOIR
3 - FLUID LEVEL SWITCH
4 - MASTER CYLINDER
5 - MOUNTING BOLT
6 - GROMMETS
Fig. 43 JUNCTION BLOCK
1 - BRAKE LINES
2 - JUNCTION BLOCK
5 - 24 BRAKES - BASEDR
FLUID RESERVOIR (Continued)

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. 44).
(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.
(4) Clamp hose shut between vacuum source and
check valve.
(5) Stop engine and observe vacuum gauge.
(6) If vacuum drops more than one inch HG (33
millibars) within 15 seconds, booster diaphragm or
check valve is faulty.
POWER BOOSTER CHECK VALVE TEST
(1) Disconnect vacuum hose from check valve.
(2) Remove check valve and valve seal from
booster.
(3) Use a hand operated vacuum pump for test.
(4) Apply 15-20 inches vacuum at large end of
check valve (Fig. 45).
(5) Vacuum should hold steady. If gauge on pump
indicates vacuum loss, check valve is faulty and
should be replaced.
Fig. 44 Typical Booster Vacuum Test Connections
1 - TEE FITTING
2 - SHORT CONNECTING HOSE
3 - CHECK VALVE
4 - CHECK VALVE HOSE
5 - CLAMP TOOL
6 - INTAKE MANIFOLD
7 - VACUUM GAUGE
Fig. 45 Vacuum Check Valve And Seal
1 - BOOSTER CHECK VALVE
2 - APPLY TEST VACUUM HERE
3 - VALVE SEAL
DRBRAKES - BASE 5 - 25
MASTER CYLINDER (Continued)

HYDRO-BOOST 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 thereshould 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. 54).
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. 54 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 - 30 BRAKES - BASEDR

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 (Fig.
61).(Refer to 5 - BRAKES/HYDRAULIC/MECHANI-
CAL/DISC BRAKE CALIPER ADAPTER -
REMOVAL)
(5) Remove the retaining clips and rotor assembly
(Fig. 61).
REMOVAL - REAR DUAL WHEELS
(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. 62).
INSTALLATION
INSTALLATION - FRONT
(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 the 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:
(4) Install the wheel and tire assembly, (Refer to
22 - TIRES/WHEELS/WHEELS - STANDARD PRO-
CEDURE) and lower the vehicle.
(5) Apply the brakes several times to seat brake
pads. Be sure to obtain firm pedal before moving
vehicle.
INSTALLATION - REAR
(1) Install the rotor to the axleshaft (Fig. 61).
Fig. 60 8 LUG ROTOR ASSEMBLY
1 - SPRING
2 - SHOCK
3 - UPPER AND LOWER SUSPENSION ARMS
4 - DISC BRAKE CALIPER
5 - DISC BRAKE CALIPER ADAPTER
6 - ROTOR
Fig. 61 REAR ROTOR
1 - ROTOR
2 - CALIPER ADAPTER
3 - CALIPER
Fig. 62 ROTOR / HUB REMOVAL
5 - 34 BRAKES - BASEDR
ROTORS (Continued)

(2) Install the caliper adapter (Fig. 61) (Refer to 5
- BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPER ADAPTER - INSTALLATION).
(3) Install the caliper adapter bolts (Fig. 61) and
tighten the mounting bolts to 135 N´m (100 ft.lbs).
(4) Install the disc brake caliper, (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPERS - INSTALLATION).
(5) Install the tire and wheel assembly (Refer to 22
- TIRES/WHEELS/WHEELS - STANDARD PROCE-
DURE).
(6) Lower the vehicle.
INSTALLATION - REAR DUAL WHEELS
(1) Install the hub to the rotor. Tighten the bolts to
128 N´m (95 ft. lbs.) (Fig. 63).
(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. 64).
(6) Install the tire and wheel assembly, (Refer to
22 - TIRES/WHEELS/WHEELS - STANDARD PRO-
CEDURE).
(7) Lower the vehicle.
SUPPORT PLATE
REMOVAL
(1) Remove wheel and tire assembly.(2) Remove the disc brake caliper (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPERS - REMOVAL).
(3) Remove the caliper adapter (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPER ADAPTER - REMOVAL).
(4) Remove the rotor (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/ROTORS - REMOVAL).
(5) Remove the axle shaft (Refer to 3 - DIFFER-
ENTIAL & DRIVELINE/REAR AXLE - 9 1/4/AXLE
SHAFTS - REMOVAL).
(6) Remove the park brake shoes (Refer to 5 -
BRAKES/PARKING BRAKE/SHOES - REMOVAL).
(7) Remove the parking brake cable from the
brake lever.
(8) Remove the bolts attaching the support plate to
the axle and remove the support plate (Fig. 65).
Fig. 63 ROTOR TO HUB
1 - Hub Bolts
2 - Socket
Fig. 64 ROTOR INSTALLED
Fig. 65 SUPPORT PLATE
1 - SUPPORT PLATE
2 - MOUNTING STUDS
DRBRAKES - BASE 5 - 35
ROTORS (Continued)

INSTALLATION
(1) Install support plate on axle flange (Fig. 66).
Tighten attaching bolts to 115 N´m (85 ft. lbs.).
(2) Install parking brake cable in the brake lever.
(3) Install the park brake shoes (Refer to 5 -
BRAKES/PARKING BRAKE/SHOES - INSTALLA-
TION). (Fig. 66).
(4) Install axle shaft, (Refer to 3 - DIFFEREN-
TIAL & DRIVELINE/REAR AXLE - 9 1/4/AXLE
SHAFTS - INSTALLATION).
(5) Adjust brake shoes to drum with brake gauge
(Refer to 5 - BRAKES/PARKING BRAKE/SHOES -
ADJUSTMENTS).
(6) Install the rotor (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/ROTORS - INSTALLA-
TION).
(7) Install the caliper adapter (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPER ADAPTER - INSTALLATION).
(8) Install the caliper (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/DISC BRAKE CALIPERS
- INSTALLATION).
(9) Install the wheel and tire assembly (Refer to 22
- TIRES/WHEELS/WHEELS - STANDARD PROCE-
DURE).
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. 67).
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.
CABLES
REMOVAL
REMOVAL - FRONT PARKING BRAKE CABLE
(1) Raise and support vehicle.
(2) Lockout the parking brake cable (Fig. 69).
(3) Loosen adjusting nut to create slack in front
cable.
(4) Remove the front cable from the cable connec-
tor.
Fig. 66 SUPPORT PLATE WITH BRAKES MOUNTED
1 - SUPPORT PLATE
2 - MOUNTING NUTS
Fig. 67 SUPPORT PLATE WITH BRAKES MOUNTED
1 - SUPPORT PLATE
2 - MOUNTING NUTS
5 - 36 BRAKES - BASEDR
SUPPORT PLATE (Continued)

(5) Compress cable end fitting at underbody
bracket and remove the cable from the bracket.
(6) Lower vehicle.
(7) Push ball end of cable out of pedal clevis with
small screwdriver.
(8) Compress cable end fitting at the pedal bracket
and remove the cable (Fig. 68).
(9) Remove the left cowl trim and sill plate.
(10) Pull up the carpet and remove the cable from
the body clip.
(11) Pull up on the cable and remove the cable
with the body grommet.
REMOVAL - REAR PARK BRAKE CABLE
(1) Raise and support the vehicle.
(2) Lockout the parking brake cable (Fig. 69).
(3) Loosen cable adjuster nut.
(4) Remove the rear park brake cable from the
intermediate park brake cable.
(5) Compress tabs on cable end fitting on the rear
park brake cable to the frame mount bracket. Then
pull the cable through the bracket.
(6) Disengage the park brake cable from behind
the rotor assembly. (Fig. 70).
(7) Compress cable tabs on each cable end fitting
at the brake cable support plate.
(8) Remove the cables from the brake cable sup-
port plates.REMOVAL - RIGHT REAR CABLE
(1) Raise and support the vehicle.
(2) Lockout the parking brake cable (Fig. 69).
(3) Loosen the brake cable at the equalizer and
adjuster nut.
(4) Remove the right cable from the front cable.
(5) Remove the right cable from the equalizer.
(6) Remove the cable from the frame bracket.
(7) Remove the cable from the axle bracket.
(8) Remove the cable bracket from the shock
bracket.
(9) Remove the brake cable from the brake lever.
(Fig. 71)
Fig. 68 Parking Brake Pedal
1 - PARK BRAKE PEDAL
2 - FRONT CABLE
Fig. 69 LOCK OUT PARKING CABLE
1 - LOCKING PLIERS
2 - PARKING BRAKE CABLE
Fig. 70 DISENGAGEMENT OF CABLE
1 - LEVER
2 - CABLE END
DRBRAKES - BASE 5 - 37
CABLES (Continued)