The Stovebolt Site Forums The Shop Area The HiPo Shop whats happening to my brakes....

have installed power brakes 1 year ago. when my truck sits a couple of days, I have to pump them to get a pedal. I have bled them a number of times. This brings the pedal back up , until I let it set agian. My first thought was a bad master cylinder, I changed to a new one last week. Drove yesterday, same problem!! I have completly checked all lines and fittings, no leaks..Any ideas? thanks

Not sure what kind of truck you have. Does it have a hydro-vac on it? Or a booster? Or what?
Scott

the truck has power brakes with a brake booster

What truck? What year, size, etc.,
Scott

what year truck ?
firewall mounted booster and master or floor mounted ?
all drum, or front disc ?
if floor mounted you will need to run residual valves for front and back.

http://www.ecihotrodbrakes.com/brake_facts.html

http://www.ecihotrodbrakes.com/images/pic03_brakefacts.gif

http://www.ecihotrodbrakes.com/images/pic04_brakefacts.gif

hope this helps...

leonard

The vacuum line to the manifold should have a one-way check valve that holds vacuum pressure for the brakes. Sounds like that may be leaking down. I'd start by replacing that. They usually are just pushed into the rubber vaccum line, you can feel it if you start squeezing the rubber tube...