The Stovebolt Site Forums The Parking Lot Big Bolts Chevrolet 6400

Hello, I am after a bit of help please. I have recently rebuilt the brakes on my 6400 chevrolet, the four wheel cylinders at the back were overhauled as was the front. I also had the master cylinder overhauled. The hydrovac was also checked and cleaned. The problem i have is when i brake the brakes work very well but they pressure up and dont let off the pressure, all the springs are ok. If you crack a bleed nipple this releases the pressure.I have checked the rubber hoses all are ok. I even removed the hydrovac and stripped and cleaned again.Any help would be appreciated. The truck is a 52 model.

Did you use the same master cylinder? Some have a pressure release valve that must be removed, some don't. Also, your Master cylinder linkage may need to be properly adjusted for length.

hello Paul

Yes i am using the same master cylinder, I have managed to nail the problem down to the master cylinder when the brakes are stuck on you can crack the pipe that connects to the master cylinder and the pressure is released. I removed the master cylinder about 2 hours ago. and gave it a good clean blowing out all the holes with my airline. I then refitted and bled the entire system so far the brakes are not sticking. Fingers Crossed.