I have repaired many problems on the truck that the previous owner did not do right. the problem that I am working on now is after bleeding the brakes and rebuilding wheel cylinders the brakes stay applied I emailed this question before and a person said make sure the the brake pedal was coming all the way up it was not the spring was off I replaced the spring and now it comes all the way up. I thought maybe the master cylinder was not assembled right the previous owner said he rebuilt it. so I removed it. I went to the rear wheels and still could not turn them with the master cylinder off the truck. so I broke the line loose on the hydrovac and left the pressure bleed off. then I could turn the wheels the previous owner installed new brake lines I was wondering if he put them on the wrong places or is there a hydrovac problem? the line in the back of the hydrovac that goes to the frame goes to the wheels I don't have a book I am sure someone here can tell me thanks for any help. the line near the center of the hydrovav goes to the master cylinder.