orbywan
Registered User
I've got a brake problem with a 95 E-350 7.3L Turbo Diesel that is driving me crazy, maybe someone can shed some light on this. I rebuilt the front end on this vehicle about a year ago and in the process replaced everything on the front brakes. Basically replaced everything you could name on the front brake system at least twice, and took the rear drums off and inspected the rear for leaks etc. The problem is, even after removing the abs brake module (the electro-mechanical block, not the abs ECU) completely and bleeding it 20 times, when you pump the pedal the brakes are great, high pedal and really solid, but when you start the engine, the pedal slowly goes all the way to the floor.
I've replaced the vacuum pump and virtually every part of the brake system except for the rear shoes and cylinders, which looked recently new with zero leaks and new shoes. I plumbed around the abs metering block thinking that was the culprit, no difference. When I plug the front port of the new master cylinder so only the rear brakes are hooked up, the pedal stays high and firm just like it should even with the engine is running.
When I re-install the front brake line to the master and start the engine, the pedal goes all the way to the floor, slowly, but all the way down. If I block the right front caliper off, the rate of fade to the floor is reduced by about half. If I block off the left caliper also, the pedal stays high and firm as you could ask for.
So, it's had two sets of rebuilt calipers and it still does it. I took it to a local shop after the first go round and they said it was the rebuilt booster, so they replaced the booster with a new Ford booster, no difference. They power bled the whole system twice, no difference.
I just read another forum where several guys described the same exact problems with the same or close to the same identical vehicle with almost the same things done, all still have the same problem and no one has posted a solution or answer except for one guy. He said he called Ford and ran it by them, they told him there was a 'pressure problem' with mid 90's E-350 vehicles and that this slow fade to the floor is normal and prevents the front wheels from locking up in spite of the abs. He asked them for some kind of written service bulletin to this effect and they said they would send him one and never did.
That post was about two years old, I just sent him an email to see if he had made any progress. Am I in the damn Twilight Zone or what? If anybody has any information or suggestions on this I would really appreciate it. Thanks!!!
I've replaced the vacuum pump and virtually every part of the brake system except for the rear shoes and cylinders, which looked recently new with zero leaks and new shoes. I plumbed around the abs metering block thinking that was the culprit, no difference. When I plug the front port of the new master cylinder so only the rear brakes are hooked up, the pedal stays high and firm just like it should even with the engine is running.
When I re-install the front brake line to the master and start the engine, the pedal goes all the way to the floor, slowly, but all the way down. If I block the right front caliper off, the rate of fade to the floor is reduced by about half. If I block off the left caliper also, the pedal stays high and firm as you could ask for.
So, it's had two sets of rebuilt calipers and it still does it. I took it to a local shop after the first go round and they said it was the rebuilt booster, so they replaced the booster with a new Ford booster, no difference. They power bled the whole system twice, no difference.
I just read another forum where several guys described the same exact problems with the same or close to the same identical vehicle with almost the same things done, all still have the same problem and no one has posted a solution or answer except for one guy. He said he called Ford and ran it by them, they told him there was a 'pressure problem' with mid 90's E-350 vehicles and that this slow fade to the floor is normal and prevents the front wheels from locking up in spite of the abs. He asked them for some kind of written service bulletin to this effect and they said they would send him one and never did.
That post was about two years old, I just sent him an email to see if he had made any progress. Am I in the damn Twilight Zone or what? If anybody has any information or suggestions on this I would really appreciate it. Thanks!!!
