4WAL Alternative Bleeding Procedure

Bleed Valve Tool:

EHCU Bleed Screw Location:

IMPORTANT

This alternative method is not intended to replace the previous procedure. It is to be used if the Tech 1/T-100 is not available or the prior procedure is unsuccessful.

1. Make sure the ignition is OFF and deplete the brake booster by pumping the brake pedal several times.

2. Ensure that the master cylinder is full.

3. Install two bleed valve tools on the 4WAL EHCU at the high pressure accumulators (HPA).


4. Install one bleed valve tool on the combination valve. DO NOT OVER TIGHTEN THE WING NUT. Doing so will result in brake fluid leaking from the combination valve.

5. Back off the two internal bleed screws on each side of the EHCU 1/4 to 1/2 turn.

6. Use a conventional bleeding process (pressure, vacuum or manual).

7. Bleed the 4WAL modulator before bleeding the wheel cylinders.

8. Open the bleed valves at the front of the modulator one at a time for approximately 10 seconds. DO NOT OVER TIGHTEN.

9. Always maintain a full master cylinder.

10. Bleed the right and left rear wheel cylinders.

11. Bleed the right front and left front wheel cylinders.

12. Remove the bleed valve depressors and tighten the side internal bleed screws. DO NOT OVER TIGHTEN.

13. Evaluate the brake pedal feel. If firm, continue with this procedure. If the pedal is soft or spongy, reinstall tools and rebleed the system, starting with step 1.

14. Perform 3 function tests using the manual test or the Tech 1 function test procedure.

15. Road test the vehicle, applying the brakes several times.