When I purchased my 49, 6400 truck a couple of years ago, I had to drive it about 250 miles to get it home. I did not know what a hydrovac was at the time. It took a lot of pressure to stop the truck on the way home. The hydrovac had been bypassed. I soon got into the hydrovac, had it rebuilt, cleaned up my brakes, replaced the rear pads and put wheel cyl kits in all 4 wheels. What a difference in braking. This truck weighs about 8000 lbs unloaded, so I am all for keeping the hydrovac working.
Jim
