Pontiac FIREBIRD 1972 Service Manual page 425

5-22 1972 PONTIAC SERVICE MANUAL
4. Attach the adjusting screw tension spring to the
shoes and install the adjusting screw. The spring
must not contact the adjusting screw star wheel.
NOTE: The right front and right rear adjusting
screws have left hand threads and can be identi-
f i e d by the number of grooves in t l ~ e adjusting
screw as f0110ws:
B SERIES
Right rear
................................................
1 wide groove.
Left rear
......................................................
1 V groove.
CAUTION:
New brake shoe return springs
should be installed if old spnngs have been
overheated or strength is doubtful. Overheated
springs may be indicated by burned paint, end
coils opened up, or failure of shoes to return to
anchor pin.
10. Sand linings lightly to remove any trace of dirt.
11. Check to see that adjuster lever can turn adjusting
screw star wheel with minimum of effort.
12. Adjust brake shoe-to-drum clearance as outlined un-
der ADJUSTMENT.
A AND X SERIES
13. Install drums.
Right front and rear
..............................
2 wide grooves.
Left front and rear
....................................
2 V grooves.
F AND G SERIES
Right rear
........................................
2 wide grooves.
Left rear
....................................................
2 V grooves.
All adjusting screws must be installed with the star wheel
end of the screw toward the rear of the car.
5. On rear brake assemblies, install the parking brake
lever to the secondary shoe and connect cable.
6. Position shoe assembly on the backing plate. Be sure
wheel cylinder links are properly positioned in the
shoe notches. On rear brakes install strut and spring
between lever and primary shoe.
NOTE: When replacing shoes, always be cer-
tain to assemble secondary shoes to the rear and
primary shoes to the front. Linings of pninary
shoes are usually shorter than secondary lin-
ings.
7. Position the upper end of actuating link over anchor
pin.
8. Engage the adjuster lever with the override pivot,
then position the adjuster lever and override spring
assembly on the secondary shoe. Fasten with the
hold-down spring assembly (Fig. 5- 15).
NOTE: THE FRONT BRAKE SPRING RE-
TAINING PINS ARE IDENTIFIED WITH
THE NUMERAL 4 (A SERIES ONLY)
STAMPED ON THE OUTER FACE. THE
REAR BRAKE RETAINING
PINS
ARE
IDENTIFIED WITH THE NUMERAL 8 (B
SERIES) OR 2 (A, F AND G SERIES)
STAMPED ON THE OUTER FACE.
Install the primary hold-down spring
9. Install the primary and secondary brake shoe return
springs.
NOTE: Front wheel bearings must be adjusted
as outlined in Section 3 of this manual.
14. If wheel cylinder has been replaced or repaired, or
hydraulic line has been replaced, bleed brakes as de-
scribed in this section on BLEEDING BRAKES.
15. Check parking brake cable adjustment and, if neces-
sary, adjust as outlined under PARKING BRAKE
-
ADJUSTMENT.
16. Check fluid level in master cylinder as shown in Fig.
5-1 1.
CAUTION: See Caution on page 1 of this Sec-
tion regarding the fasteners referred to in step
1
7
be10 w.
17. Install wheels. Tighten nuts evenly and alternately (B
Series) 75 lb. ft. (A, F and G Series) 70 lb. ft. (X
Series), 65 lb. ft. torque.
18. Check brake pedal travel to be sure it is within
specifications, then road test car for proper operation
of the brake system.
CAUTION: New linings must be protected from
severe use for several hundred miles. This
should be conveyed to owner, along with in-
structions to follow proper burnishing proce-
dure as outlined in Owner's Manual.
HYDRAULIC SYSTEM
The dual master cylinder is designed and built to satisfy
individual brake system displacement requirements (Fig.
5-2 and 5-20).
The lengths of component pistons in a master cylinder are
critical factors in displacement capabilities of a master
cylinder. Pistons are coded, using rings or grooves in
shank of piston. When pistons are replaced, replacement
piston must contain same identification marks and same
contour at push rod end as piston which was removed.