Power Brakes.

[randys4406]

I would like some advice. I have a friend asking me about replacing his brake booster and master cylinder. I am not familiar with what he is asking. He found a supplier that is asking if he wants a 1" or 1-1/8" shaft . Maybe the piston in the cylinder? Anyway the car came with power brakes and he wants to replace the booster and master cylinder. It is a 69 B body that came with a 383 automatic. Any help or leads would be appreciated.

 

[steve340]

The measurements are the bore diameter of the master cylinder.
Other than that replacing what is already there should not be to hard.

 

[PurpleBeeper]

Steve340 is correct....bore of the piston inside the master cylinder. I"m no expert on that, but some of the "race car guys" on this forum know a lot about it (maybe post on that forum?). Anyway, do some more research on what was original on the car & put in the same parts would be my recommendation.

The master cylinder is a piece of cake....but the top two (of 4) nuts under the dash that hold the booster in are TOUGH TO GET TO. I had to remove my dashboard & use a 2' extension to reach them. Also, some of the aftermarket boosters require very minor grinding to slightly enlarge the big hole in the firewall the guts of the booster go through to connect with the pedal mechanism...not too big of a deal.

 

[MoparLeo]

Any reason for the replacement ? Performance problems ? M/C leaking ? Booster leaking ? Stock replacement ? The more info, the better the answer. Price ? Big cam ? ???

 

[randys4406]

I don't know much about the rebuild. He is a friend of mine and he has a guy that is more familiar with Chevys. I have tried to help him with some parts he needed. There is an old booster and no master cylinder. Just trying to get something that will work. Don't believe the engine is much more than stock. So I wouldn't think vacuum would be a problem. I am almost thinking any stock replacement set up would work. Just threw me on the piston bore size.

 

[Islandkent]

Did you ever hear of the Ram Man? He talks at length about all kinds of Mopar brakes. He tells the differences in the different master cylinders and power and manual brake boosters. He knows his stuff.
Her is a link to his you-tube channel just check out his videos you will find it there.
https://www.youtube.com/user/THERAMMAN01

 

[Islandkent]

Here is a good place to start...

 

[randys4406]

Thanks, I have heard of mixed experiences with Ram Man. I haven't dealt with him but have met him. Seems like a nice guy. Probably have my friend contact him.

 

[Cornpatch MO]

The master cyl is easy. The booster, not so much. Where the booster push rod is, under the dash is a real PITA. There is a " toggle" linkage there that yo should take pictures of before you remove it. There is a coil spring that attaches to the push rod and goes up to the under dash bracket for the pedal. I have no idea what that is for, and the factory service manual is not very clear on it..... I am converting to power brakes , and the rebuilt booster and correct master cylinder is available from O' Rileys--$165.00 for both , and that includes core charge.......MO

 

[randys4406]

The master cyl is easy. The booster, not so much. Where the booster push rod is, under the dash is a real PITA. There is a " toggle" linkage there that yo should take pictures of before you remove it. There is a coil spring that attaches to the push rod and goes up to the under dash bracket for the pedal. I have no idea what that is for, and the factory service manual is not very clear on it..... I am converting to power brakes , and the rebuilt booster and correct master cylinder is available from O' Rileys--$165.00 for both , and that includes core charge.......MO

Thanks, I will pass that on

 

[Dragon Slayer]

He should replace what he has with the same no? He already has power brakes, so is the original? Is it drum or disc? The 69 B body used Bendix for power disc and the piston was a 1 1/8". If this is a power drum set up, the MC and booster are different. If this is just a mixed and match set up, you still need to know what type of brakes on the front, to match a correct MC and get a booster that will work with it.

 

[randys4406]

Yes thanks, Just replacing the power booster and cylinder for existing drum brakes.