The Stovebolt Site Forums The Shop Area General Truck Talk Double master cylinder for 66?

Slow going on the bodywork but slowly making progress. I've been looking at the brakes and I don't like the single master cylinders the 66 and older trucks came with and would like to update to a 67 or newer double style. For the time being I won't be getting into disc or even power brakes, I just want a simple replacement of the master cylinder for safety reasons. Truck is a 66 GMC 1/2 ton with manual drum brakes. Has anybody done the same swap and what did you use?

Dave:

Converting to power brakes on the '64-'66 Chevy truck is a dramatic upgrade of the stock braking system on these trucks and the parts are readily available. Additionally, you can use your single chamber master cylinder. If you install a dual chamber master cylinder, it will likely be coupled with a power brake booster, I believe, therefore you may as well go with a factory power brake booster. Good luck with your project.

Tony

A 67-8 master for manual brakes will fit either the stock 64-66 booster or straight to the firewall IIRC. If you decide to go disc a 71-2 manual master fits the stock 64-66 booster. There is a TEE in the brake line under the engine, replace this with a coupler to couple the front lnes back together, then add the second line down to the rear line that was previously attached to the TEE. Brian

What does IIRC mean in the previous post? Thanks

If I Recall/Remember Correctly,,

Is that true about the 67-68 mc being a direct bolt in? Is the push rod length the same also? I have been contimplating how to get my '66 over to a dual circuit system. That would certainly probably be the easiest and cheapest way.

Those are my concerns, I might have to head off to the boneyard this weekend and see if I can find a 67-8 to snag some parts from. Don't want to get into problems with pushrod lengths etc if I can avoid it now. Might look at finding a power booster too if it is just a simple bolt on. I know the drum system isn't perfect but can't afford and don't have the time for too many upgrades right now. Son will be 16 in September and he wants to be driving so I need the truck safe and legal by then.

I used a dual master from a '67 purchased from NAPA. I had to extend the linkage using a barrel nut, but it worked fine.