So I've spent several hours searching around for an answer, to no avail. This is not a case of having to push the pedal to the floor for brakes, or having to push the pedal hard for the brakes to work.

My truck ('86 B2) had been siting for a bit when I started it and stepped on the brake pedal. The brakes locked up, and I was unable to move the truck at all. The pedal was stuck on the floor, and wouldn't come up even with me prying it up a bit.

First thought anyone has when there are brake problems is the master cylinder, so I took it off. That allowed me to free up the brakes to move the truck (slowly, and using the emergency brake to stop it when I got it where I wanted to move it so I could work on it), but the brake pedal was still stuck. After a bit, I tried prying it up a little harder... still with my hand, but it took a significant amount of pressure to get it back up off the floor.

It would seem -- since the brakes actually applied when the brake pedal was depressed -- that the master cylinder is working. Can the booster actually grab the brake pedal and keep it from releasing? It's been sitting there with no master cylinder for a several days, and it was depressed and forced to release a couple of times when I was messing with it several days ago. I just went out there and depressed the brake pedal with a little effort (no power, no master cylinder), and had to pry it back up again.

Thank you in advance for any help.

Thoughts?

- JoN

 

Is'nt there a rod that goes through the firewall, we trouble with that on our big trucks. We had to pull it out and lube it up. Or maybe the pivot bushing in your pedal.
I have no idea.

 

The air valve is stuck shut on the booster, with engine vacuum it will apply the brakes. I broke my 89 F250 booster with a 2x4 cut to hold the pedal up and shot WD40 up into the vent area(inside cab where brake rod goes into the booster) But best to replace the booster. or just remove the vacuum line from it(no power brakes then)