The ABS brake system must be bled using Anti-lock Test Adapter T90P-50-ALA, or equivalent. If the procedure is not followed correctly, air will stay trapped in the Hydraulic Control Unit (HCU) which will lead to a spongy brake pedal.
- To bleed the master cylinder and the HCU, connect the anti-lock tester wiring harness to the 55-pin harness connector of the ABS module.
- Place the bleed/harness switch in the bleed position.
- Turn the ignition switch to the ON position.
- Push the motor button on the tester down, starting the pump motor. The pump motor will run for 60 seconds.
- After 20 seconds of pump motor operation, push and hold the valve button down. Hold the valve button down for 20 seconds.
- The pump motor will continue to run for an additional 20 seconds.
- The master cylinder and HCU should be free of air and the brake lines must now be bleed using the conventional method for non-ABS brake systems by bleeding the wheels in the following sequence: right-hand rear, left-hand front, left-hand rear and right-hand front.
- Road test the vehicle and check for proper brake system operation.
Whenever service is performed on the ABS valve block or pump and motor assembly, the following procedure must be performed to make sure no air is trapped in the ABS control and modulator assembly. If this procedure is not done, the vehicle operator could experience a spongy pedal after the ABS is actuated. This procedure requires the use of the Ford New Generation STAR (NGS) Tester, or equivalent.
- First bleed the entire brake system conventionally as outlined earlier in this section.
- Reattach the NGS Tester to the data link connector as though retrieving codes.
- Make sure the ignition is in the RUN position.
- Follow the instructions on the NGS screen. Choose the correct vehicle and model year, go to DIAGNOSTIC DATA LINK menu item, choose ABS MODULE, choose FUNCTION TESTS and choose SERVICE BLEED.
- The NGS will prompt you to depress the brake pedal. Make sure you press hard on the brake pedal, and hold it down for approximately 5 seconds while the NGS opens the outlet valves in the brake pressure control valve block. When the outlet valves are opened, you should immediately feel the pedal drop. It is very important that you continue pushing the pedal all the way to the floor. The NGS will then instruct you to release the brake pedal. After you release the brake pedal, the NGS will run the ABS hydraulic pump motor for approximately 15 seconds.
- Repeat the previous step to ensure that all air is bleed from the ABS unit. Upon completion, the NGS will display SERVICE BLEED PROCEDURE COMPLETED.
- Repeat the conventional bleeding procedure.
- Once complete, road test the vehicle and check for proper brake system operation.
See Figure 1