The Stovebolt Site Forums The Parking Lot Big Bolts 54 hydrovac in a 41?

I put one on my 40 gmc 250 with a 270. The difference in braking was amazing. Since having a 51 6100 dump and a GMC 350 firetruck I had scrounged hydravacs and rebuilt a couple of them. Where I live you need a good working units. Since the 40 250 was a flat bed it was more of a novelty having it on the truck. In my experience with them the exterior can look crappy as hell due to where their located. The inside of the can has to be perfectly smooth and no pitting anywhere. The pilot valve body also needs to be pristine on the inside. Lots of white corrosion builds up in them preventing them from operating correctly. Sandblast exterior surfaces, install with a new kit and spray paint. It will look and work like new. The good thing with the Chevy is the vent is in the cab and you can hear it working when your braking. Gmc's are mounted on the firewall in engine compartment.