The Stovebolt Site Forums The Parking Lot Big Bolts C65 hydrovac

I have a friend with a 1976 C65 Chevrolet dump truck. He bought a 1989 C65 chassis to update his truck. He used the cab and also the front axle. The front axle from the newer truck had disc brakes on it so he thought he was making an improvement to his truck using it. He installed the master cylinder from the '76 truck and used the same hydrovac from the truck. The Bendix # for the hydrovac is #2513812. Now he has a high pedal effort and marginal brakes. I'm looking for some help to get the correct hydrovac and master cylinder for the front disc brakes / rear drum brakes that he has on the truck now. The '89 parts truck he bought originally had a 8.2 diesel in it. The master cylinder and hydrovac off that truck are long gone.
Thanks, Don

From what a lot of guys on here say about him,I'd talk to Midwest Power Products,in Morris,Il. (Rich),(815)943-0550. References on page Two,here on "Big Bolts: "Hydrovac's-Is There A Way To Get Rid of Them?" Good Luck,Don!

Hy don stocker, a disc/drum braking system must use a dual master cylinder for a disc/drum system. If your system currently uses a single Hydrovac, another Hydrovac must be added for the second system. Disc brake systems do not have or require residual pressure valves, unless the master cylinder is mounted below the level of the disc brake calipers and then only a 2 p.s.i. residual pressure valve is required in order to stop drainback to the master cylinder, dual master cylinders for drum brakes have a residual pressure valve built into each system, hope that helps.

Thanks,3B. You're exactly right! I just figured Rich would know what M.C./hydrovac combo word work,since he sounds pretty knowledgable on the subject,even on the "obsolete" ones. He might even have a unit in-stock? Now that's wishful thinking!

Here is the correct phone number for Rich @ Midwest Power Products,
815-942-0550

http://midwestbooster.com/

One digit off willy.
I had a nice chat with Rich and he is going to help my friend get the correct stuff for his truck. He was telling me that the later Chevrolet trucks don't use the same hydrovac that the earlier trucks use. They have 2 different systems that are used. One type has a 13" vacuum booster that mounts to the firewall with the master cylinder mounting to it. The other type system uses power from the power steering pump.

Don

Good News!!