Pressure

Bleeding is necessary if air has entered the hydraulic brake system. It may be necessary to bleed the system at all four wheels if a low fluid level allowed air to enter the system, or the brake pipes have been disconnected at the master cylinder or combination valve. If a pipe is disconnected at one wheel, then only bleed that wheel.

The time required to bleed the hydraulic system when the master cylinder is removed can be reduced by bleeding the master cylinder before installing it on the vehicle.

If the Brake Pressure Modulator Valve (BPMV) has been replaced or has air trapped in it, refer Antilock Brake System, BPMV. Service and Repair

Pressure Bleeding (Alternate Method)

Tools Required:
^ J 41618 A Brake Bleeder Adapter Set
^ J 39177 Combination Valve Pressure Bleeding Tool
^ J 29567 Brake Pressure Bleeder or equivalents

A diaphragm type pressure bleeder must be used. It must have a rubber diaphragm between the air supply and brake fluid to prevent air, moisture, oil, and other contaminants from entering the hydraulic system.

NOTICE: Brake fluid will damage electrical connectors and painted surface. Use shop cloths, suitable containers, and fender covers to prevent brake fluid 1from contacting these areas. Always reseal and wipe off brake fluid containers to prevent spills.

1. Fill the pressure tank at least 2/3 full of brake fluid.

^ The bleeder must be bled each time fluid is added.

2. Charge the bleeder to 140-170 kPa (20-25 psi).
3. Use J 39177 to depress and hold the metering stem of the combination valve mounted on the BPMV assembly.

Brake Bleeder Adaptor:

4. Install J 29567 and J 41618-A Brake Bleeder Adapter Set.
5. If the BPMV of the 4WAL system is replaced or suspected to have air trapped inside, it must be bled next. Refer to Antilock Brake System, Service and Repair.
6. Connect the hose from the bleeder to the adapter at the master cylinder.
7. Open the tank valve.
8. Attach a hose to the bleeder valve at the right rear wheel.
9. Immerse the opposite end of the hose into a container filled with clean brake fluid partially
10. Open the bleeder valve at least 1/2 to 1 turn and allow the fluid to flow until no air is seen in the fluid.
11. Tighten the bleeder valve to 7 Nm (62 lb in).
12.Bleed each wheel in the following sequence:
A. Right rear
B. Left rear
C. Right front
D. Left front
13. Remove J 39177.
14. Use a Scan Tool to perform four 4WAL function tests.
15. Re-bleed each wheel circuit.
16. Check the brake pedal for "sponginess."

^ Repeat the bleeding procedure if this condition is found.

17. Turn off the valve on the bleeder.
18. Disconnect the hose from the bleeder adapter.
19. Remove the bleeder adapter.
20. Fill the master cylinder to the proper level.
21. Check the brake pedal feel.