Hey, so the brakes in my truck just starting acting weird the other day. The truck has a hydroboost system, and has always had great brakes. All of the sudden the other day I was backing into a parking spot and the pedal went soft. It went pretty much to the floor, but the truck still stopped, I let the pedal out and it was firm again. Then it happened in the next parking lot It only happens when I'm maneuvering the truck in a parking lot. When the pedal comes back out, I can hear a suction noise by the pedal. There are no leaks that I can find, and once the pedal comes back out, it is very firm, almost touchy, which is the way it normally is.


I recently found a dry rotted cap on a vacuum line on the j-tube and since I replaced it, the trucks idle will dip when coming off throttle to about 400rpm do you think this has anything to do with it???

 

Have you checked your PS fluid?