Manual Bleeding

MANUAL BLEEDING

NOTICE: Brake fluid will damage electrical connections and painted surfaces. Use shop cloths, suitable containers, and tender covers to prevent brake fluid from contacting these areas. Always re-seal and wipe off brake fluid containers to prevent spills.

Tool Required: J 28434 Wheel Cylinder Bleeder Wrench

- Relieve the vacuum reserve by applying the brakes several times with the ignition "OFF"

1. Fill the master cylinder reservoirs with Delco Supreme No. 11 Hydraulic Brake Fluid (GM P/N 1052535) or an equivalent DOT 3 motor vehicle brake fluid.

- Maintain the fluid level during bleeding.

2. If the master cylinder is suspected to have air in the bore, bleed it before any wheel cylinder or caliper.
A. Disconnect the forward brake pipe connection at the master cylinder.
B. Allow the brake fluid to flow from the connector port.
C. Connect the brake pipe but do not tighten.
D. Slowly apply the brake pedal and allow the air to bleed from the loose fitting.
E. Tighten the fitting before releasing the pedal.
F. Wait 15 seconds.
G. Repeat this sequence, including the 15-second wait, until all air is purged from the bore.
H. After all air has been removed from the forward connection, repeat this procedure for the rear pipe.

3. If the BPMV of the 4WAL system is replaced or suspected to have air trapped inside, it must be bled next. Refer to With ABS.

4. Bleed each wheel in the following sequence:
A. Right rear
B. Left rear
C. Right front
D. Left front

5. Attach J 28434 to the wheel cylinder/caliper bleeder valve.

- Immerse the opposite end of the hose into a container partially filled with clean brake fluid.

6. Slowly apply the brake pedal one time and hold.
7. Loosen the bleeder valve to purge the air from the wheel cylinder/caliper.
8. Tighten the bleeder valve and slowly release the pedal.
9. Wait 15 seconds.
10. Repeat this sequence, including the 15-second wait, until all air is purged from the wheel cylinder/caliper.
11. Tighten the bleeder valve to 7 N.m (62 lbs. in.).
12. Continue steps 5 through 11 at each wheel until the system is bled.
13. Check the brake pedal for "sponginess" and the brake warning lamp for an indication of unbalanced pressure. Repeat the bleeding procedure to correct either of these conditions.