I just had to replace all my steel brake lines on my 1997 exp. After I was done went to do a bleed and no pressure builds when truck is running, builds pressure with truck off but disappears when started. Changed M/C but always had suspicion it was air in ABS. Have read here that needs to be bled on a scanner, so I bought an actron plus Cp9410 OCB II but it gives no error messages. Will this scanner do it? Is scanner bad?

 

No, you would need the scanner the dealer has, or an equivalent. Their scanner can activate and open the ABS valves and allow the fluid to pass.

 

Here is the actual brake bleeding procedure.

If equipped with the 4 wheel anti-lock brake system and the Hydraulic Control Unit (HCU) has been replaced or is suspected of containing trapped air; bleed the brake system using the procedure below. Conventional brake system bleeding cannot remove the air trapped in the lower portion of the HCU. If a spongy brake pedal is present and air in the hydraulic control unit is suspected, use the following procedure:

1. Bleed the brake system as outlined in the conventional bleeding procedure.
2. Connect a New Generation Star (NGS) tester or equivalent scan tool, to the serial data link connector below the instrument panel as though retrieving codes.
3. Make sure the ignition switch is in the RUN position.
4. Follow the instructions on the NGS screen. Verify correct vehicle and model year go to the "Diagnostic Data Link' menu item, choose ABS Module, choose "Function Tests", and choose "Service Bleed."

5. Bleed the right-front wheel as follows:
---A. Open the caliper bleed screw and pump the brake pedal for 3 seconds. Repeat the procedure again.
---B. When the fluid runs clear, begin the program and continue to pump the brake pedal.
---C. Continue bleeding for approximately 1 to 2 minutes after the program ends and then tighten the bleed screw.
6. Repeat the bleeding procedure to the left-front, left-rear and finally the right-rear wheel.
7. Remove the pressure bleeding device and adjust the brake fluid level.
8. Road test the vehicle and check for proper brake system operation.

 

Thanks for the reply, don't like your answer but I think that you are right on. It also might answer an ongoing prob that I've had with my f250 superduty diesel. It has rear ABS and a few years ago when I had brake probs it developed another problem. It would NOT relieve the brake pressure in the rear brakes. After about the 3rd time you use the brakes I have to crack the rear bleeder because the pressure builds and rear pads brings truck to a standstill. The fluid is not returning to the m/c. (I assume its not returning through the ABS system)

 

I've seen this happen when the flexible brake hose needs to be replaced. What happens is a piece of the hose material breaks away from the wall inside the hose and flaps. This has the effect of being a one way valve. It lets the fluid go in one direction, but when the fluid tries to return, the pressure holds the flap tight and blocks off the hose.

 

both calipers and all lines (steel and rubber) rear wheel to whell have been replaced