Master Cylinder

[matchframe]

I have the master cylinder that came with my HydraBoost brakes. It originally was a part of an anti-lock brake set-up on a '92 Chevrolet 1 ton dually truck. The HydraBoost fits perfectly in place of the vacuum booster.

My question is;

Can I use this master cylinder on my '78 Vette?

Are master cylinders used with anti-lock brakes different from any other master cylinder?

Thanks,
Bill

 

[MaineShark]

The bore diameter of the cylinder may not be the same as with your original master cylinder. If so, the volume of fluid that is displaced will be different. Since modern brakes tend to use smaller bores, that means less fluid, and the possibility of not fully actuating the calipers.

Will your original master cylinder bolt up to the booster?

Joe

 

[matchframe]

The original Vette master cylinder does bolt to the booster. The hydraulic ports on both master cylinders look to be the same size, but the later one may have more of a restriction inside. I just could not tell by looking.

The newer one has the plastic reservoir whereas the older one is one piece metal...built in reservoir.

Bill

 

[Hib Halverson]

Not only may the master cylinder bore diameter be different, but the fitting theads may differ, as well. A master cyl. from a 78 probably has SAE threads and the cyl. off the 92 3500 pick-up may have metric (ISO) threads.

In addition, the Corvette cylinder is designed for four wheel disc brakes and the 92 3500 probably has discs and drums. My guess is the truck cylinder may have a smaller reserviour for the rear brakes and possibly a proportioning valve for the rears as well, both reasons not to use it for a 4WHL disc application.

If your Corvette master has failed, they are fairly easy to overhaul. All you need is a brake hone and a rebuild kit.

 

[JohnZ]

The truck master cylinder (if it's from a disc/drum system) will also have a residual pressure valve (RPV) in the rear outlet port to maintain 8-10 psi in the rear system; disc systems don't use them.

 

[matchframe]

Thanks!!

The 3500 does have drums on the dually axle and discs up front.

The Vette master cylinder does need to be rebuilt. I think I will just rebuild it and use it with the HydraBoost.

Thanks again!

Bill