Hey guys,
Master cylinder went this weekend... straight to the floor with or without vacuum and no fluid loss.

So I have a list of questions...
Should I replace the brake booster while I'm at it? I'm assuming so, but would like opinions.

Is a specific brand/type that's better or more reliable than others?

I've got front discs/rear drums... Should I look into converting over to rear discs at this point? Nothing on the car is original other than the M/C which just went so I wanted to know if anyone switched over to rear discs and would recommend it.

Figured I'd ask the people who have gone through it before ordering parts somewhat blindly

Thanks guys
Jim

 

I'd buy a new $35 master cylinder and be on your way. The majority of your braking is from the front. Rear discs are over rated IMO.

 

I thought the same thing about the rears but figured I'd ask.

I'm thinking about replacing the booster only because it's over 50 years old... how do you tell if they're good or not, and how often do they fail? I don't want to put in a new M/C only to have the booster go next year or something like that

 

I had to replace the master cylinder on my '73 Custom Cruiser last February. I replaced the booster at the same time for exactly the reasons you state, even though it was working fine. I had the master cylinder off already, so changing the booster would be simple, the one on the car was the original, 41-year-old booster, and I would hate to have gone through all the trouble of removing, bleeding, and replacing the master cylinder only to have to do it all over again a month later if the booster failed.

By the way, "how do you know if they're good or not" is kind of an odd question. You would have no power brakes if your booster was no good! You'd know in an instant.

 

Couldn't have said it better. Don't overthink this.

- Eric

 

After thinking about it, I'm probably going to replace the booster and master... only because it's 46 years old at this point and I don't want to have to redo it.

Anyone know any reputable brands? Rockauto has the A1cardone refurbished ones and OPGI has a decent looking combination, both are around $150. Any other sources or vendors I should be looking at?

Thanks for all the help guys
Jim

 

I bought both the master cylinder and brake booster at Autozone. Installed last February and no problems so far.

The master cylinder was a new Fenco unit (never heard of that brand, but whatever), cost $20, and they had it in stock. The booster was a Cardone unit, remanufactured, cost $109, and had to be ordered in the store and picked up a day or two later.

Autozone does show a combined master cylinder/vacuum booster for $94.99 plus core charge for your car:

http://www.autozone.com/autozone/par...2_772298_8550_

Lifetime warranty. Order in store.

 

Looked at this thread and I have a similar situation. 68 Cutlass S Holiday Coupe. It's been sitting for 15 years on jack stands in my garage. My sons are finally old enough to get interested in working on it. We did some engine mods and other obvious maintenance.


Long story short, when we were ready to drive out of the garage last weekend I put my foot on the brake and it went straight to the floor. opened the reservoir lid and it was dry.


My question is: should I just try refilling the MC, bleeding all four wheel cylinders and then check for leaks? Or should I go ahead and replace the MC? What about the wheel cylinders after sitting that long?


Grandmasolds

 

You don't know where the fluid went, so I would fl it and try to pump it up first.
You may find it squirting out of a rusty line, or peeing out of a wheel cylinder.
Once you know where the fluid went, you can decide how many parts to change.

- Eric

 

Thanks, I will give that a try first.


Todd

 

Don't forget that the leak might be from the master cylinder itself. Last winter the dash brake light went on on my '73 wagon. First thing I did was check the M/C, and one reservoir (the front one) was empty. Next thing I did was look at the garage floor where the car had been parked, figuring I'd see a puddle somewhere telling me which cylinder was leaking or whatever. Nothing. Which was why, I figured, the loss of fluid caught me by surprise. I don't check the brake fluid reservoir that often, figuring that if there as ever a leak anywhere, I'd see it on the garage floor. As I learned, not true!

I ultimately determined that the brake fluid was seeping out of the M/C as much of the lower half of the brake booster where it attaches to the M/C had a sheen of brake fluid on it. Apparently it had leaked so slowly that there was never enough build-up to drip on the floor. It just evaporated off the booster. A new M/C fixed the problem, and, as I said, I threw a new booster on at the same time.

Since the OP's car has been sitting for 15 years, it's entirely possible that the fluid could have leaked out of the M/C onto the booster, floor, orwherever and had time to evaporate. This all could have happened 5 or 10 years ago if no one was paying attention to the car.

So, yes, fill it back up, work the pedal, and look for leaks. Just be sure to include the master cylinder among the places you look.