General Information

Procedure Scope

The Auto Bleed Procedure is used to provide a complete brake system bleed on Teves Mark IV equipped vehicles. The procedure cycles the system valves and runs the pump to purge air from secondary circuits normally closed off during non-ABS/TCS mode operation and bleeding. It is to be used when it is suspected that air has been ingested into the system secondary circuits, or when the Brake Pressure Modulator Valve (BPMV) has been replaced with a new unit.

Required Equipment

To perform this procedure successfully, the following are required:

- Scan tool.
- A pressure brake bleeder capable of producing at least 30 psi. with suitable adapters and filled with Delco Supreme 11 brake fluid obtained from a sealed container.
- A hoist, or suitable stands to support vehicle.
- A bleeder bottle to receive vented brake fluid. The bottle should be constructed of unbreakable plastic, and should have a clear plastic hose size to fit snugly on the bleeder valves. The hose should protrude into the bottle, with its end immersed in brake fluid.
- An assistant to pump the brake pedal during the procedure.
- Suitable safety attire, including safety glasses.

Bleed Instructions

Note: The Auto Bleed Procedure may be terminated at any time during the process by pressing the EXIT button. No further scan tool prompts pertaining to the Auto Bleed procedure will be given. After pressing EXIT, relieve bleed pressure and disconnect bleed head from master cylinder, following bleed equipment manufacturers instructions.

1. Raise vehicle and support.
2. Remove all four wheels.
3. Inspect brake system for leaks or component damage. Correct all conditions found before starting procedure.
4. Assure vehicle battery is fully charged before beginning procedure.
5. Connect scan tool to DLC.
6. Turn Ignition to RUN, do not start engine.
7. Establish communications with scan tool and select ABS/TCS system features.
8. Select MISCELLANEOUS TESTS
9. Select AUTOMATED BLEED PROCEDURE.
10. Bleed base brake system.
11. Follow scan tool menu driven instructions until proper brake pedal height is achieved. If any malfunctions are detected, the bleed procedure will be aborted. If DTCs are present, the scan tool will display DTCs PRESENT, or list the DTCs, depending on when the DTCs were set. DTCs can be displayed or cleared as appropriate in the "Trouble Codes" mode. Refer to the correct Service Manual section for those DTCs. If the test is aborted but no DTCs are listed, go to the Diagnostic System Check in this section. Correct all system malfunctions before attempting the bleed procedure again. If a road test is required for diagnosis and brake pedal is " spongy," perform a conventional brake bleed, achieving a firm pedal before driving the vehicle.
12. When the Auto Bleed Procedure is complete, depress brake pedal. It should be high and firm. If not, re-inspect brake system thoroughly for any conditions which could cause excess brake pedal travel. If brake system is OK, and excess pedal travel persists, repeat Auto Bleed Procedure.
13. Disconnect scan tool. Reinstall wheels and tires and lower vehicle. Check brake fluid level in reservoir and fill if necessary. Road test vehicle, making several ABS and Traction Control actuations in a suitable area. Brake pedal should remain high and firm after road test.