Pontiac FIREBIRD 1972 Service Manual page 414

BRAKES
-
GENERAL 5-1 1
SERVICE OPERATIONS
INSPECTING BRAKE SYSTEM
4. Withdraw brake pedal, spacer and nylon bushings.
Complete brake system inspections must be performed at
least every 12,000 miles. Need for future service should be
REPLACE
estimated at this time.
All metal and rubber brake lines should be checked for
1. Lubricate and install nylon bushings and spacer in
cracks, leaks, and evidence of chafing. The master cylin-
pedal hub. (Manual brakes on A Series with cruise
der and wheel cylinders should be checked for leaks.
control
-
install return spring on pedal hub.)
Brake shoe return springs must be replaced if evidence of
excess heat is found.
2. Install brake pedal in support brace.
It is particularly important that the brake fluid level is
3. Slide pedal pivot shaft bolt through support brace
correct and that linings have not worn beyond safe limits.
and pedal hub.
Any necessary corrections should be made as outlined in
this manual.
In addition, each time the car is serviced for any reason
there is an opportunity and obligation to check the operat-
ion of the brake system. For example, each time the car
is lubricated, or if the car is raised on a lift, brake lines,
hoses, and cables should be visually inspected for signs of
chafing, deterioration, or other damage. A careful check
for leaks should also be made. If the brake pedal has
excessive travel when brakes are applied, or if pulls, grabs,
or other irregularities are noted, a need for brake service
exists. No car should leave the service department with
brakes that are not safe. Repairs as necessary should be
made as outlined in this manual.
BRAKE PEDAL
REMOVE
NOTE: Refer to Section I A for removal of air
conditioning components i f necessary.
1. A, X, F and G Series
-
Remove brake pedal clevis pin
retainer and pin (Figs. 5-5, 5-6, 5-7, 5-8, 5-9).
B Series (Power Brake)
-
Clevis pin is part of pedal
assembly (Fig. 5-4).
2. Remove nut from brake pedal pivot bolt.
NOTE: The brake pedalpivot shaft bolt is also
the clutch pedal pivot on all manual transmis-
sion models. A separate bolt, located at top of
mounting bracket, is used on Pontiac with
PO
wer brakes.
CAUTION: See Caution on page I of this Sec-
tion regarding the fasteners referred to in step
4 be10 w.
4. kstall nut on pedal pivot shaft bolt and torque to 30
lb. ft.
5. Install clevis pin (A, X, F and G Series), and retainer,
(all models).
NOTE: Retainer must
be
tight enough to scn&e
a mark on pin as installed.
PEDAL HEIGHT
Pedal height is not adjustable, and no attempt should be
made to change this factory setting. A, X, F and G Series
-
The zip-on nut which holds the clevis to the pushrod
must be firmly seated.
CAUTION: Ifpedal bracket prevents full return
of brake pedal and master cylinder push rod,
the master cylinder pistons may
be
prevented
from returning to their stops. This can block o f f
the compensating ports which prevents brake
shoes from returning fully when the pedal is
released. A further complication which folows
a blocked compensating port is lining drag and
rapid brake burnup. It is necessary that the
primary cups
be
entirely clear o f the compen-
sating ports to provide a safety factor against
nonnal rubber swell and expansion and deffec-
tion of body parts and pedal linkage.
3. Slide pedal pivot shaft bolt to left enough to clear
BRAKE WARNING LIGHT CHECKING PROCEDURE
brake pedal.
NOTE: Manual brake pedals on A Series vehi-
cles with cruise control have a return spnng on
the pedal hub (Fig.
5-5).
NOTE: Caution should
be taken to prevent air
from entenng hydraulic system dunng checks
on switch.