Pontiac Fiero 1988 Service Manual page 229

1-8 BRAKES
c. Connect the forward brake pipe to the master
cylinder and tighten.
d. Depress the brake pedal slowly one time and
hold. Loosen the forward brake pipe connec-
tion at the master cylinder to purge air from the
bore. Tighten the connection and then release
the brake pedal slowly. Wait 15 seconds.
Repeat the sequence, including the 15 second
wait, until all air is removed from the bore. Care
must be taken to prevent brake fluid from con-
tacting any painted surface.
e. After all air has been removed at the forward
connection, repeat step d and bleed the master
cylinder at the rear (cowl) connection.
f. If it is known that the calipers do not contain any
air, then it will not be necessary to bleed them.
3. Individual calipers are bled only after all air is
removed from master cylinder.
a. Place a proper size box end wrench or tool
J 21472 over the bleeder valve. Attach a clear
tube over bleeder valve and allow tube to hang
submerged in a clear container partially filled
with brake fluid. Depress the brake pedal
slowly one time and hold. Loosen the bleeder
valve to purge the air from the cylinder. Tighten
bleeder screw and slowly release pedal. Wait
15 seconds. Repeat the sequence, including
the 15 second wait until all air is removed. It may
be necessary to repeat the sequence ten or
more times to remove all the air. Rapid pumping
of the brake pedal pushes the master cylinder
secondary piston down the bore in a way that
makes it difficult to bleed the rear side of the
system.
4. If it is necessary to bleed all of the calipers, the follow-
ing conventional sequence should be followed:
a. right rear
b. left rear
c. right front
d. left front
5. Check the brake pedal for "sponginess" and the
"BRAKE" warning lamp for indication of unbalanced
pressure. Repeat entire bleeding procedure to cor-
rect either of these two conditions.
Pressure Bleeding (Figures 7 and 8)
Tools Required:
J 29532 Bleeder
J 29567 Bleeder Adapter
J 21472 Bleeder Wrench
NOTICE: Pressure bleeding equipment must be
the diaphragm type and must have a rubber dia-
phragm between the air supply and the brake fluid to
prevent air, moisture, oil and other contaminants
from entering the hydraulic system.
1. Install the bleeder adapter to the master cylinder.
2. Charge bleeder to 140-172 kPa (20-25 psi).
3. Connect line to adapter. Open line valve and depress
bleed-off valve on top of adapter until a few drops of
fluid appear.
4. Raise car. See Section OA.
Figure 8 Plastic Reservoir Master Cylinder Pressure
Bleeder Adapter (Typical)
5. Bleed the brakes in the following sequence:
a. right rear
b. left rear
c. right front
d. left front
6. Place a proper size box end wrench or J 21472 over
the bleeder valve. Attach a clear tube over valve and
allow tube to hang submerged in a clear container
partially filled with brake fluid.
7. Open the bleeder valves at least 3/4 turn and allow
flow to continue until no air is seen in the fluid.
8. Close the bleeder valves.
• Be sure they seal.
9. Repeat steps 6 through 8 until all calipers have been
bled.
10. Lower car. See Section OA.
11. Check the brake pedal for "sponginess" and the
"BRAKE" warning lamp for indication of unbalanced
pressure.
• Repeat entire bleeding procedure to correct
either of these two conditions.
12. Remove brake bleeding equipment from master cyl-
inder.
FLUSHING B R A K E HYDRAULIC S Y S T E M
It is recommended that the complete hydraulic system be
thoroughly flushed with clean brake fluid whenever new
parts are installed in the hydraulic system.
The system must be flushed if there is any doubt about
the grade of fluid in the system or if fluid has been used
which contains the slightest trace of mineral oil.
All rubber parts that have been subjected to a contami-
nated fluid must be replaced.
Approximately one-quart of fluid is required to flush the
hydraulic system.