Preparation Procedure
The auto bleed procedure provides a complete brake system bleed on Teves
Mark IV equipped vehicles.
The procedure cycles the system valves and runs the pump in order to
purge air from secondary circuits. These secondary circuits are normally closed
off during non-ABS/TCS mode operation and bleeding.
Use the auto bleed procedure under either of the following conditions:
• | When suspecting that the air has been ingested into the system
secondary circuits |
• | When the Brake Pressure Modulator Valve (BPMV) has been replaced
using a new unit |
Bleeding Procedure
Notice: 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 exiting the bleed procedure, relieve
bleed pressure and disconnect bleed equipment per manufacturers instructions.
Failure to properly relieve pressure may result in spilled brake fluid causing
damage to components and painted surfaces.
- Suitably support and raise the vehicle. Refer to
Lifting and Jacking the Vehicle
in General Information.
- Remove the 4 wheels.
- Inspect the brake system for leaks or component damage.
Correct any problems before beginning the procedure.
- Ensure that the vehicle battery is fully charged.
- Connect the scan tool to the DLC.
- Turn the ignition to RUN.
Do not start the engine.
- Establish communications with the scan tool.
- Select ABS/TCS system features.
- Select MISCELLANEOUS TESTS.
- Select AUTOMATED BLEED PROCEDURE.
- Bleed the brake system. Refer to
Hydraulic Brake System Bleeding
in Hydraulic Brakes.
- Follow the scan tool menu driven instruction in order to achieve
the proper brake pedal height.
• | If any malfunctions are detected, the bleed procedure will be
aborted. |
• | If DTCs are present, the scan tool will either display the message
DTCs PRESENT or list the DTCs. (This depends on when the DTCs were set.) DTCs
may be displayed or cleared, as appropriate, in the trouble codes mode.
Refer to the applicable section for each DTC. |
• | Correct all system malfunctions, and attempt the bleed procedure again. |
• | If a road test is required for diagnosis and the brake pedal is spongy,
perform a conventional brake bleed. Achieve a firm pedal before driving the
vehicle. |
- When the auto bleed procedure is complete, depress the brake pedal.
The pedal should be high and firm. If the pedal is not high and firm,
reinspect the brake system thoroughly for any conditions that may cause excess
brake pedal travel. Refer to
Diagnostic System Check - ABS
.
If the brake system is OK but excess pedal travel exists, repeat the
auto bleed procedure.
- Disconnect the scan tool.
- Reinstall the wheels and the tires.
- Lower the vehicle.
- Inspect the brake fluid level in the reservoir. Fill the reservoir
if necessary. Refer to
Master Cylinder Reservoir Filling
in Hydraulic Brakes.
- Road test the vehicle.
• | Make several ABS and TCS actuations in a suitable area. |
• | The brake pedal should remain high and firm after the road test. |