1972 C10 Power Brake Upgrade

[rharris]

I added a brake booster to my truck today. A few tips I learned along the way

1) plan for extra work/parts. Drivers side wheel cylinder was leaking a little so I decided to replace it. The brake line fitting was rounded so I had to cut the brake line and add a small piece of line. Also, if ordering wheel cylinders, make sure you order the proper cylinders. I noticed summit had one part number, but classic parts had a separate for each side. The stock has the line inlet at the rear of the cylinder. I would imagine the summit standard cylinder would work, however the brake lines line up with the proper cylinder for the side.

2) Make sure if you're going from manual to power brakes that you have the proper fire wall boot for the push rod. I found this out after I had the bracket and realized that I needed the boot. My patience sucks, so I had to wait a few days until the boot came.


3) Order the proper booster. There is a Bendix and a Delco. Some people have said they are interchangeable, and they may be for some applications. They were not on my truck with a stock power brake bracket (guess how I know). The Bendix bolt pattern on the bracket side didn't match, and the Bendix had a threaded master cylinder pushrod with a nut on the end. The Delco had correct bolt pattern and push rod.


4) Order a master cylinder for power brakes. I'm not sure if the manual MC works, but the bore depth seemed larger in the manual MC.

5) If money isn't an issue, and you plan to keep the drum brakes in rear, I would change both cylinders and pads while in there.

6) Speed Bleeders make the one man bleeding job much easier and are relatively cheap.

7) The pedal will not rest against the rubber stop as the manual brake setup did. Adjust the brake light switch at pedal prior to connecting push rod. there isn't much room under there. And, I ended up using a 17mm for the brake light switch nuts - seemed strange but its what fit.

My parts list

Master Cylinder - Summit, Part# DHB-M71285 $39.99
Bracket and Booster Core - Forum Member (Thanks Al) $20
Booster - Summit, Part# AAZ-54-71125 $57.99 plus $20 core charge
Wheel Cylinder - Classic Parts, Part# 71-128 right & 71-127 left $19.95 each
Push Rod Boot - Classic Parts, Part# 71-287 $7.95
Manifold Vacuum T - Ebay, 3/8" NPT and 3/8" and 1/4" barbs - $10
Speed Bleeders, Summit, Part# Rus-639590 $9.99/pair
3/8" Vacuum Tubing - Closest parts store - few bucks

[rharris]

Pics with Booster. Couldn't load in original post for some reason

[BCOWANWHEELS]

72,s had disc brakes on front

[rharris]

Originally Posted by BCOWANWHEELS

72,s had disc brakes on front

and drum on the rear

[GASoline71]

All of those parts should be available from a local parts house. When I redid the entire brake system on my 1972 GMC C15, the only thing I didn't get from a parts house was the booster and M/C. Got those from CPP mainly because of the look. Other than that... rotors, calipers, pads, drums, shoes, drum brake install kit, wheel cylinders, and the 3 soft lines all came from my local parts store over the counter. I put up an old pic from when I installed it.

Oh... I also installed an entire Stainless Steel brake line kit from Inline Tube.

I still need to fine tune my brake pedal and probably readjust the rod attached to it. The pedal doesn't come back up against the rubber stop every time. So sometimes I have to pull it up with my toe.

Gary

[rcazwillis]

Originally Posted by rharris

I added a brake booster to my truck today. A few tips I learned along the way

Excellent information. This is one of the changes we are making to Zane's 71. Thanks for posting info that will most definitely save us some time.

[rharris]

Below are a few other options. I wanted to try to do it as cost effective as I could. I almost went the captian bracket route for looks, but im happy with the turnout.

http://67-72chevytrucks.com/vboard/s...d.php?t=720837
http://67-72chevytrucks.com/vboard/s...d.php?t=347484

[rharris]

Gary,

Inline tube is my fall project, along with new shoes and springs. Did you find the bracket at your parts store? I looked for one but couldn't find anything with a bracket and pushrod that would bolt right in. My pedal is about 1" from the rubber stop. From what I've read, power brake trucks didn't use the stop.

[GASoline71]

The bracket came with the booster I got from CPP. Only thing I don't really like about it is it sticks out from the firewall about a inch further than the stock bracket I had there.

As I get further and further and further into this project... I'm probably gonna ditch the booster and go with a Corvette non-power brake master cylinder. 1. to clean up the engine bay a little. 2. The truck is heading towards more strip than street. 3. The cams I use usually don't make much vacuum so I have to use either a canister or run a vacuum pump.

Gary

[rharris]

Hydro an option?

[GASoline71]

Could run a hydro as well. But just don't really have a need for power brakes.

Gary

[BCOWANWHEELS]

I have a new hydro setup if anyvody needs 1