Dodge Dakota (R1). Manual — part 231

rear drum brakes. The front disc brakes consist of
single piston calipers and ventilated rotors. The rear
brakes are dual brake shoe, internal expanding units
with cast brake drums. The parking brake mecha-
nism is cable operated and connected to the rear
brake secondary shoes. Power brake assist is stan-
dard equipment. A vacuum operated power brake
booster is used for all applications.

Two antilock brake systems are used on this vehi-

cle. A rear wheel antilock (RWAL) brake system is
standard. An all-wheel antilock brake system (ABS)
is available as an option.

DESCRIPTION

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.

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

5 - 2

BRAKES - BASE

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.

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, damaged
tires.

NOTE: Some pedal pulsation may be felt during
ABS 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.

BRAKES - BASE

5 - 3

BRAKES - BASE (Continued)

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Dodge Dakota (R1). Manual — part 231

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