update on brakes

[melvin92]

Well, I put a new vacuum pump in and it did nothing, still having the same problems as before. When I just tap the brake pedal it will go slowly to the floor by itself, then come right back up. It is also squashy when you put the brake on. And when I'm driving sometimes the brake will go to the floor and back up by itself.

Any help would be great.
Thanks.

[zpd307]

if you had no power assist, hard pedal, i would have guessed vacuum pump or brake booster. this could be a bad master cylinder or wheel cylinders... not sure if a faulty rabs valve would do this. does the brake light on the dash come on?

[melvin92]

Brake light? Are you talking about the parking brake light?
If so , no that light does not come on. Is there another light that should come on?

[zpd307]

you should have a "brake" light on the dash that lights up when the master cylinder loses fluid or fails. idk if the parking brake uses the same light.

[takif350]

Some trucks use the same light some dont from what it sounds like to me is a bad master cylinder I am a BMW tech but I work on customers tow vehicles also most of the time Ford trucks and have seen this before in multiple Ford trucks and it has been the master replace it and do a very good brake bleed Pete

Originally Posted by melvin92

Brake light? Are you talking about the parking brake light?
If so , no that light does not come on. Is there another light that should come on?

Just make sure you dont have any leaks first especially in the rear of the truck ie brake line wheel cylinders

[fastback11]

Ford had a problem with the master cylinder bore size being to small. The fix was to use a master cylinder from a '96 it has the increased bore size to fix the problem. I was trying to replace what I thought was a faulty master and had installed 3 of them a bleed with a 4 wheel power bleeder. I still had marginal brakes. I went to the ford dealer to purchase a factory part and the parts manager said to use the '96 part on my '93. I installed the recomended part and it was fixed. Good luck.