NOS brake master cylinder

ubercrap · Post by **ubercrap** » Fri May 28, 2004 7:27 am

Will it still be any good?

Edit: I hope so, I just bought it!

DeathBus · Post by **DeathBus** » Fri May 28, 2004 11:13 am

If it is still packed in fluid it should be, I just sold one that I had in my parts cabinet for a couple of years, the guy put it in and said it works perfect.

ubercrap · Post by **ubercrap** » Fri May 28, 2004 11:36 am

It's in its original packaging as it was sitting on an import shop shelf for the last 25 years. Is that how they came packaged?

raygreenwood · Post by **raygreenwood** » Fri May 28, 2004 11:43 am

Generally they are good. But... The life will be short. Expect about 1-2 years max. You need to dis-assemble that cylinder and clean everything . The brake paste used on those parts is mostly coal oil or mineral oil. Look for rust pits on everything and corrosion on the compensating port, brass flaps.
The problem is that over time, the seals harden up and take a set. They have a hard time expanding properly to seat on the walls. I ended up ditching the stock master cylinder. I am using a new 22mm bus cylinder mounted where the cut-out is in the trunk for the power brake unit. I fabbed a fulcrum and pushrod from old Audi parts...looks like factory. Bent some new lines. It has pressure nearly equal to that of the power brake version. I hated to change anything original that much....but it is still at least in the stock location where power brakes would have been. Also, it works better than the stock cylinder....is much easier to replace, work on...and does not screw up my carpet whenever I work on it. Ray

DeathBus · Post by **DeathBus** » Fri May 28, 2004 12:08 pm

I'll let you know in 1 or 2 years how the guys master is doing on his car

ubercrap · Post by **ubercrap** » Fri May 28, 2004 1:06 pm

I guess that might give me some time to get the tools to figure out another solution.

raygreenwood · Post by **raygreenwood** » Fri May 28, 2004 3:24 pm

Get a rabbit master cylinder ($30) or a type 3 FAG kit and steal the seals and compensating port valves...dump the pistons and cylinder in the trash. If the new cylinder is smooth...it will last just like a new one. I have also gone the route of building an under dash bolt-up bracket to use a late super master cyclinder. It was slightly unbalanced on its fluid volume. I dumped it and went with the bus cylinder. As long as the volume is as high or higer than the original type 4 cylinder, it will work great. Ray