Does anyone have experience in replacing hydrovacs on a Chevy or GM medium duty truck? I'm told that I may need a pressure bleeder after I change it out, and that even with this, it's hard to bleed air out of the brakes. My local mechanic said he could swap this out for $750 which seems a little steep for me. This is the type of booster I have on my truck: 2508827 Bendix NEW Hydrovac 2512065 Chevy GM Trucks 2508827 Chevy C60 Hydrovac Booster acemotorparts.com I'd like to try to install this myself and save the money if possible. Thanks in advance!
With these systems ive messed with i mean this in the kindest way possible. Take a torch and cut the truck in to little pieces. Really if you can bleed brakes properly you can most likely handle it. Is the rest of the system in good shape. I wouldnt be a bit suprised if the rest of it needs rebuilding also
Yes, everything actually seems to be in good shape. The previous owner installed new wheel cylinders front and back, and the brake fluid was flushed and replaced at that time. I've just never changed one of these. I think I will give it a try and avoid paying the mechanic.
I don’t think it’s possible to bleed all the air from a OG hydrovac system in 2025. I’m surprised a legit mechanic would even touch that system unless they replaced everything. Otherwise, there is no way to warranty or stand behind the work. It’s guaranteed to be a comeback. Nobody will be happy. It’s nothing but heartache and broken dreams under that hood. Probably have to purchase five brand-new units to find one that works. Probably, won’t even get the correct one. I mean, my guy Tyler d4c is willing to spend the money in acetylene to exact his revenge and action of violence on a truck that never even hurt him. That says something.
Bleed the master cylinder to hydrovac first, there will be a bleeder on it, making sure you keep master full of fluid. It takes two people, one to pump pedal one to open bleeders. The person in cab pushes pedal with slow full depression three times, holds pedal down while person at bleeder opens it, when fluid/air stops bleeder is shut first then the pedal can be released. Do not let pedal come up while bleeder is open, after two sessions of bleeding check master fluid level, do not let it run dry. Once only clear fluid is seen with no air at hydrovac, move to the right rear wheel bleed it first, then the left, then the right front, then the left. It can be done manually, it's been done that way for years in garages across the country. Otherwise the first time one needed brakes it would have been buy a new truck.
Well, sure. If one wishes to be be logical and methodical about it. But, the matrix has changed. .
Spock.
Just the childhood trama of trying to keep a loadstar for the one farmer working. I quote dad "push it let up push it let up why isnt there no fluid i told you to fill the master" its empty dad " well fill the f$%%&$ thing up this dont let it run dry" to this day the brakes still dont work on that pile due to not beingable to get a correct hydrovac.
Well those should have been named {Deadstar}.
Most likely I have no clue how you could drive it comforably and 345 cubes of never get there on time
Make sure the depth in the master cylinder piston is the same as the old one also. ( Where the brake pedal rod goes ) 1/8" or so difference cost me a day or so of my life. Do not have the old one? Good luck. Those were always fun systems to bleed.
When Deadstars were built---no one was in a hurry, no cell phones.
I would try to convert it to a hydromax system out of a later truck. Runs off its own belt driven pump and has an electric pump built into the booster in case the engine quits.
Probably more than truck is worth.