A fellow Mopar enthusiast contacted my car club and told us he has a '67 GTX with a brake problem. He's has trouble working on cars himself and asked if someone would help him out with replacing his master cylinder and power brake booster. I volunteered to be the guy to help out.

After he spent some time chasing down parts I finally got to see the car today. Here is the situation:

He has a factory '67 GTX with a 440 and an automatic trans. The car originally came with manual drum brakes but at some point in time about 10 years ago he wanted disc brakes and bought a disc brake conversion kit from a company who is now no longer in business. All he remembers is that they were in Aimes, Iowa. It is a weird setup to my eye because all I have ever worked on is mainly old Mopars and some newer cars and I've never seen a master cylinder like this. He thinks it may fit a Corvette. The problem is sometimes the pedal goes to the floor and the car has no brakes. He took the car to a professional mechanic and the mechanic said the master cylinder is bad. However, the MC is no longer made in the same exact configuration as what he has. I told him to get that particular MC rebuilt but he said it would be too costly. He wants to change the MC and the power brake booster to a factory Mopar PBB/MC. Someone sold him on the idea of using a '74 PBB and MC. After looking at the car and the parts I see two problems with this idea. #1) I have a '70 E body which is pretty close to a '74 B Body. He doesn't have the small linkage/lever assembly that is needed on my car and many other cars to use the PBB. Also where the sleeve/bushing and bolt go under the dash for this linkage/lever assembly on his car there is a 2" space and on my car there is a 3" space. Now that is for an E body linkage/lever assembly. Is there a '68 B body linkage/lever assembly that will fit the 67? Problem #2) is that the PBB itself measures out to 11" in diameter and the one he has in there is only 8" in diameter[approximately]. I think there is a good chance the '74 PBB will hit the inside of the inner fender and not even be able to be bolted in. If not it will be tight up against it or at least very close to it.

So I am thinking the '74 B Body parts are not going to work. Has anyone ever converted a '67 B Body to power disc brakes using factory parts? If yes, how did you do it? How about '68 power brake parts will that work? I believe power drum brakes were an option in '68.

Earlier in this process I told him to contact MP Brakes and he did. Problem is he said they won't sell him a PBB/MC setup unless he buys the entire conversion kit.

Thanks in advance for any help.

couple of choices I think.

there are a few ebay companies that sell master power brake parts, but not the whole kit. a quick search shows 3 just the power booster and master cylinder for around 250.
should bolt up to just the pedal.

second is disc brakes were an option in 68. not positive about for b body's but should have been a dual diaphram booster you can get for that year that will be smaller than the 74.

finally, I cannot believe they had a custom made master made. most of the company's use the 60's era corvette boosters. mine is the same thing but has ports on both sides.

I even took it up to the parts store to make sure I could get another. just ask for a 74 vett mc. see if it matches bolt pattern wise.

I've got a '67 Satellite, but can't help much. I wonder if a search in the Tech Archives here in Moparts might help with information how others have done it, or a search in Mopar Action's archives.
Best of luck, -Art

Andrewh, you're probably right about the MC. He did say he thinks it fits a Corvette but I didn't really understand why another one can't be bought. Maybe he is not sure of the exact kind of Corvette that it fits.

Anyway, he is on a tight budget and I honestly believe the most cost effective solution is to get the current MC rebuilt. I've seen a bunch of ads in Hemmings from guys that rebuild master cylinders. I have suggested this to him and he hasn't gotten back to me.

If it were my car I would want it to be as close to original as possible. Rock Auto has a listing for a '67 booster and MC but it is for power drum brakes. I would get that booster and whatever parts are needed to hook it up to the pedal and then find a MC and proportioning valve that works with disc brakes. But that's just me and my obsessive self.

Thanks a lot for the replies.

here is the catch with using a drum master cylinder.
they don't apply enough force for disc brakes.

while I have not done it for a b-body, I did use the power drum booster for a c-body with a disc brake upgrade.

you could not lock up the brakes.

it was still way better than drums, but not as good as they could have been if I had used the disc booster.

it should be easy enough to check, and rebuilding it may not be as cost effective as getting a reman. especially if it is just a common chevy master cylinder.
autozone carries a reman for 17 bucks. shipping would be more.