Brake Issues


New Member
Authorized Seller
Sep 4, 2008
Fairfax, VA

I had been losing break fluid out of my break reservoir for several years but it has always been very slow so did not take action on it. When the dash light would come on I would top off the reservoir and the light would go off. This past weekend my father was driving my car (89-Turbo) to get in inspected and checked the break fluid before he took it out. On the way back from the inspection the brake pedal went to the floor and he lost all breaking ability. He was coming up to a turn at the time and was not going that fast so was able to stop with the e-brake.

We had the car towed back home and upon inspection the front of the brake reservoir was empty but there was still fluid in the back of the reservoir. Upon inspection the front of the brake booster was wet underneath the master cylinder. I'm thinking the two grommet seals on the bottom of the master cylinder need to be replaced and the seal between the master cylinder and break booster.

I also removed the vacuum line going from the engine area to the brake booster. The line was completely dry. I had read if break fluid from the master cylinder was leaking into the booster it could cause issues and the line would be wet.

So my overall question is what should I replace to fix the issue? I'm thinking of replacing the master cylinder and the seals. I'm thinking the brake booster is fine and would not need to be replaced. How would I confirm that?

Also how would I test to make sure the problem is fixed before taking the car back on the road. I would not want to be driving and having the breaks fail again.

Thanks in advance.


Abe's 1987

Authorized Seller
Sep 5, 2017
If the brake booster failed your breaks should be weak even with the reservoir full. But with a leaking master cylinder I'd expect the same weakness. Yes I would at least start with new seals in the reservoir and drive it a couple of times in your neighborhood. If it still leaks you should be able to determine with just a couple short drives.