2
-1
PART 2-1 PAGE PART 2-3 PAGE
GENERAL BRAKE SERVICE
..........
.2-1
SPECIFICATIONS
..............
.2-20
PART 2-2
BRAKE SYSTEM
.................
.2-6
PART
2-1
GENERAL BRAKE SERVICE
Section Page Section Page
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1 Diagnosis and Testing
.....................
.2-1
3 Cleaning and Inspection
.2-4
2 Common Adjustments and Repairs
.........
.2-3
DIAGNOSIS AND TESTING
PRELIMINARY TESTS
1.
Check the fluid in the master
cylinder, and add
FoMoCo
heavy-
duty
brake fluid as required.
2.
Push the brake pedal down as
far as it will go while the car is
standing. If the car is equipped with
power brakes, the engine should be
running while making this test. If the
brake pedal travels more than half-
way between the released position
and the floor, check the automatic
adjusters for being inoperative. To
check adjuster operation, inspect the
brake shoes and the adjuster mech-
anisms for binding or improper in-
stallation and follow the procedure
described under "Brake Shoe Adjust-
ments" in Part 2-2, Section 2.
Make several reverse stops to en-
sure uniform adjustment at all
wheels. This procedure applies to
power brakes only.
3.
With the transmission in neu-
tral, stop the engine and apply the
parking brake. Depress the service
brake pedal several times to exhaust
all vacuum in the system. Then, de-
press the pedal and hold it in the
applied
position. Start the engine.
If the vacuum system is operating,
the pedal will tend to fall away un-
der foot pressure and less pressure
will be required to hold the pedal
in the applied position. If no action
is felt, the vacuum booster system
is not functioning. Follow the pro-
cedures in the "Booster Diagnosis
Guide".
4.
With the engine shut off, ex-
haust all vacuum in the system
(power brakes only). Depress the
brake pedal and hold it in the ap-
plied position. If the pedal gradually
falls away under this pressure, the
hydraulic system is leaking. Check
all tubing hoses, and connections for
leaks.
If the brake pedal movement feels
spongy, bleed the hydraulic system
to remove air from the lines and
cylinder. See "Hydraulic System
Bleeding", Section 2. Also, check
for leaks or insufficient fluid.
5.
Should one of the brakes be
locked and the car must be moved,
TROUBLE SYMPTOMS, CAUSES, AND CORRECTIONS
open the brake cylinder bleeder
screw long enough to let out a few
drops of brake fluid.
This bleeding
operation will release the brakes,
but it will not correct the cause
of the trouble.
ROAD TEST
The car should be road tested
only if the brakes
wilI safely stop
the car.
Apply the brakes at a speed
of 25-30 mph to check for the exist-
ence of the trouble symptoms listed
in Table 1, with the exception of
those resolved in the preliminary tests
and brake chatter. For each of the
symptoms encountered, check and
eliminate the causes which are also
listed
in
Table 1. To check for brake
chatter or surge, apply the brakes
lightly from approximately 50 mph.
BOOSTER DIAGNOSIS GUIDE
For booster removal and installa-
tion procedures, refer to Part 2-2,
Section 3. For disassembly and as-
sembly procedures, refer to Part 2-2,
Section
4.
For cleaning and inspec-
tion refer to Part 2-1, Section 3.
BOOSTER INOPERATIVE-
HARD PEDAL
If the preliminary tests show that
the booster is inoperative or if a
hard pedal condition still exists after
eliminating the causes of "Hard
Pedal" listed in Table 1, the trouble
may be caused by vacuum leakage.
Disconnect the vacuum line at the
booster, remove the vacuum mani-
fold and check valve assembly, and
look for a sticking or faulty check
valve. Check all vacuum connections
for leakage or obstruction. Check all
hoses for a leaking or collapsed con-
dition. Repair or replace parts as
necessary.
If the foregoing procedure does
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