Brake problem

[paintedreams]

Well to start with I have just finished my trans converison from a E4OD to a ZF5 and now I have a brake issue. I didn't have this problem before but now when you press the brake pedal lightly it will depress out from under your foot and the truck will start to slow down without any pressure on the pedal then when you push the pedal to stop and you release it the pedal doesn't come back up for a few seconds at the same time the brakes want release till the pedal comes up. I have noticed that I can pull the pedal up by hand and it will release also. I think it might be the brake booster does anyone think thats the problem or what could it be?

 

[Black dawg]

Since it didnt do this before, I would check that the booster linkage is not binding or something wierd like that. the pedal staying down sounds an awful lot like a linkage problem. Since you were working by that rabs valve I would take a look at that also. I have seen those valves cause a lot of wierd pedal feel and dragging/not releasing rear brakes

 

[paintedreams]

Can you be more specific on the components.

 

[Black dawg]

the linkage i was refering to is what connects the brake pedal to the booster. Make sure it is on right, and make sure that the pedal assy moves freely. The rabs valve is the antilock brake valve on the inside of left frame rail up by the front of the transmission

 

[Magoo]

When you converted to man trans did you change the whole pedal asymbly? Isnt there a heavy spring on the pedal pivot? Is it in one piece? Just a thought. Did you have to crake a brake line to do the conversion?