InvisiBill
Active member
I ran across this in my Chilton's, and hadn't seen it here before. It states "1991-92 MFI-Turbo", though I think the unit is the same for all SyTy's. You can turn a bleeder on each side of the ABS unit to open up the valving inside to bleed it. There are regular brake bleeders on top of the unit.
The combination valve tools are relatively inexpensive and should be available from various aftermarket companies. Although a homemade tool may suffice, DO NOT attempt to fabricate a homemade tool unless you are CERTAIN it will not damage the valve/bleed stem by over-extension.
1. Make sure the ignition is in the OFF position to prevent setting false trouble codes.
2. Open the internal bleed valves 1/4 - 1/2 turn each.
3. Install J-35856 or equivalent combination valve depressor tool on the left accumulator bleed stem of the EHCU. Install one tool on the right bleed stem and install the third tool on the combination valve (rear).
4. Inspect the fluid level in the master cylinder, filling if needed.
5. Have an assistant slowly depress the brake pedal and hold it down.
6. Open the left bleeder on top of the unit. Allow fluid to flow until no air is seen or until the brake pedal bottoms.
7. Close the left bleeder, then have your assistant release the pedal slowly and wait 15 seconds.
8. Repeat these steps starting with depressing the brake pedal (including the 15 second pause), until no air is seen in the fluid.
9. Tighten the left internal bleed valve to 60 inch lbs. (7 Nm).
10. Bleed air from the right bleeder screw on top of the EHCU in the same manner as the left screw.
11. When bleeding of the right port is complete, tighten the right internal bleed valve to 60 inch lbs. (7 Nm).
12. Remove the 3 special combination valve tools.
13. Check the master cylinder fluid level, refilling as necessary.
14. Bleed the individual brake circuits at each wheel.
15. Switch the ignition ON and use the hand scanner tool to perform 3 function tests on the system.
16. Evaluate the brake pedal feel and repeat the bleeding procedure if it is not firm.
17. Carefully test drive the vehicle at moderate speeds; check for proper pedal feel and brake operation. If any problem is noted in feel or function, repeat the entire bleeding procedure.
The directions are as you sit in the seat. Left is the fender side and right is the engine side. The left side is for the rear brakes and the right side is for the front brakes.
A lot of people have had good results from simply bleeding the brakes to clear strange ABS codes. I'm wondering if it would help even more to bleed out the ABS unit itself too. Seems like it could only help.
The combination valve tools are relatively inexpensive and should be available from various aftermarket companies. Although a homemade tool may suffice, DO NOT attempt to fabricate a homemade tool unless you are CERTAIN it will not damage the valve/bleed stem by over-extension.
1. Make sure the ignition is in the OFF position to prevent setting false trouble codes.
2. Open the internal bleed valves 1/4 - 1/2 turn each.
3. Install J-35856 or equivalent combination valve depressor tool on the left accumulator bleed stem of the EHCU. Install one tool on the right bleed stem and install the third tool on the combination valve (rear).
4. Inspect the fluid level in the master cylinder, filling if needed.
5. Have an assistant slowly depress the brake pedal and hold it down.
6. Open the left bleeder on top of the unit. Allow fluid to flow until no air is seen or until the brake pedal bottoms.
7. Close the left bleeder, then have your assistant release the pedal slowly and wait 15 seconds.
8. Repeat these steps starting with depressing the brake pedal (including the 15 second pause), until no air is seen in the fluid.
9. Tighten the left internal bleed valve to 60 inch lbs. (7 Nm).
10. Bleed air from the right bleeder screw on top of the EHCU in the same manner as the left screw.
11. When bleeding of the right port is complete, tighten the right internal bleed valve to 60 inch lbs. (7 Nm).
12. Remove the 3 special combination valve tools.
13. Check the master cylinder fluid level, refilling as necessary.
14. Bleed the individual brake circuits at each wheel.
15. Switch the ignition ON and use the hand scanner tool to perform 3 function tests on the system.
16. Evaluate the brake pedal feel and repeat the bleeding procedure if it is not firm.
17. Carefully test drive the vehicle at moderate speeds; check for proper pedal feel and brake operation. If any problem is noted in feel or function, repeat the entire bleeding procedure.
The directions are as you sit in the seat. Left is the fender side and right is the engine side. The left side is for the rear brakes and the right side is for the front brakes.
A lot of people have had good results from simply bleeding the brakes to clear strange ABS codes. I'm wondering if it would help even more to bleed out the ABS unit itself too. Seems like it could only help.