Manual Bleeding

WARNING:
- Do not move the vehicle until a firm brake pedal is obtained. Failure to obtain a firm pedal before moving vehicle may result in personal injury.
- Use only SUPREME 11 (GM P/N 1052542), or equivalent DOT 3 brake fluid from a clean, sealed container. Do not use fluid from an open container that may be contaminated with water. Improper or contaminated fluid could result in damage to components, or loss of braking, with possible personal injury.
- Overfilling the reservoir must be avoided due to the potential for overflow onto the nearby catalytic converters in the exhaust system. Brake fluid is flammable, and contact with hot exhaust components could result in a fire and possible personal injury.

CAUTION:
- If any brake component is repaired or replaced such that air is allowed to enter the brake system, the entire bleeding procedure MUST be followed.
- Avoid spilling brake fluid on any of the vehicle's painted surfaces, wiring, cables or electrical connectors. Brake fluid will damage paint and electrical connections. If any fluid is spilled on the vehicle, immediately flush the area with water to minimize the potential for damage.

NOTE:
- Prior to bleeding the brakes, the front and rear displacement cylinder pistons must be returned to the top/most position. The preferred method uses a Scan Tool to perform the rehoming procedure. If a Scan Tool is not available, another procedure may be used, but it is extremely important that the procedure be followed exactly as outlined. Piston Rehome Information


1. Clean brake fluid reservoir cover and surrounding area.
2. Remove brake fluid reservoir cover. Inspect brake fluid level in reservoir and fill to the correct level if necessary.
3. Install brake fluid reservoir cover.

Brake Bleeding:

4. Prime ABS brake modulator/master cylinder assembly.
a. Attach a bleeder hose to rearward bleeder valve and submerge opposite hose end in clean container partially filled with clean brake fluid.
b. Slowly open rearward bleeder valve.
c. Depress brake pedal and hold until fluid begins to flow.
d. Close valve and release brake pedal.
e. Repeat Steps (b) through (d) until no air bubbles are present.
f. Relocate the bleeder hose to the forward brake modulator bleeder valve and repeat Step 4.
g. Tighten ABS brake modulator bleeder valves to 9 Nm (80 inch lbs.).

CAUTION: Once fluid is seen to flow from both modulator bleeder valves, the ABS brake modulator/master cylinder assembly is sufficiently full of fluid. However, it may not be completely purged of air. At this point move to the wheel brakes and bleed them. This ensures that the lowest points in the system are completely free of air and then the ABS brake modulator/master cylinder assembly can be purged of any remaining air.

5. Remove brake fluid reservoir cover.
6. Install brake fluid reservoir cover.
7. Prime the Traction Control Module (TCM).
a. Remove TCM bolt to bracket to access bleeder valves.
b. Attach bleeder hose to right side bleeder valve and submerge opposite hose end in clean container partially filled with clean brake fluid.
c. Slowly open the bleeder valve.
d. Depress brake pedal and hold until fluid begins to flow.
e. Close valve and release brake pedal.
f. Repeat Steps 7B through 7E until no air bubbles are present.
g. Relocate the bleeder hose to the left side bleeder valve and repeat Step 7.

CAUTION: Once fluid is seen to flow from both bleeder valves, the TCM is sufficiently full of fluid. However, it may not be completely purged of air. At this point move to the wheel brakes and bleed them. This ensures that the lowest points in the system are completely free of air and then the TCM can be purged of any remaining air.

h. Tighten the:
- TCM bleeder valves to 9 Nm (80 inch lbs.).
- TCM bolt to bracket to 5 Nm (44 inch lbs.).

8. Remove brake fluid reservoir cover. Inspect brake fluid level in reservoir and fill to the correct level if necessary.
9. Install brake fluid reservoir cover.
10. Raise vehicle and suitably support.
11. Proceed to bleed wheel brakes in sequence shown:

(1)Right Rear (2)Left Front (3)Left Rear (4)Right Front.

a. Attach a clear bleeder hose to bleeder valve at the wheel and submerge opposite hose in clean container partially filled with clean brake fluid.
b. Open bleeder valve.
c. Slowly depress brake pedal.
d. Close valve and slowly release brake pedal.
e. Wait 5 seconds.
f. Repeat this step until the brake pedal feels firm at half travel and no air bubbles are observed in the bleeder hose.
g. Tap lightly on the caliper or braking plate to dislodge any trapped air bubbles, then tighten the:
- Front caliper bleeder valve to 13 Nm (115 inch lbs.).
- Rear wheel cylinder bleeder valve to 7 Nm (62 inch lbs.).

CAUTION: Make sure the bleeder valves do not leak.

12. Lower vehicle.
13. Remove brake fluid reservoir cover and inspect brake fluid level in reservoir and fill to the correct level if necessary.
14. Install brake fluid reservoir cover.
15. Bleed the ABS brake modulator/master cylinder assembly.
a. Attach a clear plastic bleeder hose to rearward bleeder valve on the ABS brake modulator. Submerge opposite hose end in clean container partially filled with clean brake fluid.
b. Depress brake pedal with moderate force.
c. Slowly open rearward bleeder valve and allow fluid to flow.
d. Close valve and release brake pedal.
e. Wait five seconds.
f. Repeat Step 15 until no air bubbles are observed in the bleeder hose.
g. Relocate the bleeder hose on the forward brake modulator bleeder valve and repeat Step 15.
16. Bleed the TCM.
a. Attach a clear plastic bleeder hose to right side bleeder valve on the TCM. Submerge opposite hose end in clean container partially filled with clean brake fluid.
b. Depress brake pedal with moderate force.
c. Slowly open the bleeder valve and allow fluid to flow.
d. Close valve and release brake pedal.
e. Wait five seconds.
f. Repeat Step 16 until no air bubbles are observed in the bleeder hose.
g. Relocate the bleeder hose on the left side of the TCM bleeder valve and repeat Step 16.
17. Remove brake fluid reservoir cover and inspect brake fluid level in reservoir and fill to the correct level if necessary.
18. Install brake fluid reservoir cover.
19. Inspect.
a. Turn the ignition to the "RUN" position, turn engine off. Apply brake pedal with moderate force and hold. Note pedal travel and feel.
1) If pedal feels firm and constant and pedal travel is not excessive, start the engine.
^ With the engine running, re-check the pedal travel.
^ If it's still firm and constant and pedal travel is not excessive, go to next step.
2) If pedal feels soft or has excessive travel either initially or after engine start, the following procedure may be used.
^ With the Scan Tool, release then apply each motor 2 to 3 times and cycle each solenoid 5 to 10 times.
^ Apply the front and rear motors to ensure the pistons are in the upmost position.

WARNING: DO NOT DRIVE THE VEHICLE.

^ If a Scan Tool is not available, remove foot from brake pedal, start the engine and allow it to run for at least 10 seconds to initialize the ABS.

WARNING: DO NOT DRIVE THE VEHICLE.

^ After 10 seconds, turn the ignition off. This initialization procedure MUST be repeated 5 times to ensure any trapped air has been dislodged.
^ Repeat bleeding procedure.
b. Road test the vehicle.
1) Make several normal (non-ABS) stops from a moderate speed to ensure proper brake system function.

WARNING: Allow adequate cooling time between stops.