I've pinpointed my leak,it's coming from the bottom bolt under the booster/ master cylinder. I tried to tighten it, but it still leaks pentosin (green drops). Any suggestions?

I've pinpointed my leak,it's coming from the bottom bolt under the booster/ master cylinder. I tried to tighten it, but it still leaks pentosin (green drops). Any suggestions?

You have the classic booster "O" ring leak. There is a "O" ring inside that needs to be replaced, it can be done with the booster in place but you have to separate the master cylinder from the booster.

There is a ma-moo spring inside the booster so it is a cautious job, can be a DIY if you are handy and mechanical, if not better left to a professional. Don't let anyone try to sell you a new booster, the "O" ring is a NAPA part and costs less then a dollar. I am not in my shop now but will post the "O" ring part # tomorrow.

Grazie Mille

You have the classic booster "O" ring leak. There is a "O" ring inside that needs to be replaced, it can be done with the booster in place but you have to separate the master cylinder from the booster.

Agree, The new brake booster is $600+ while the O ring is $0.73. I don't remember the part # either as Jon had a Stock of those O rings and let me have a couple.

The O-ring is actually $0.98 and can be found at NAPA. Ask for a BELKAMP #72-72222. Be careful with the spring and the retainer discs. Although I have done this with the booster in the car (once) as well as out of the car - out of the car is alot better. Be very careful when removing the brake-light switch in order to disengage the booster coupling, but it is fairly straight forward.

Thanks all for the info. This will be my second "surgery", wish me luck. Are there any additional tips besides the springs and clips that I should be aware of?

use blue locktite on that one screw you will be removing.

Thanks all for the info. This will be my second "surgery", wish me luck. Are there any additional tips besides the springs and clips that I should be aware of?

Here is Jon's instruction document (http://www.e31faq.com/attachments/att89.pdf).

Good luck.

Ahmed,
Thanks for the write up. This should prove Very useful

Tx,
I'll be sure to use the lock tite

I was thinking, since i'm there, does anyone know of anything else I should do/ replace in that area?

I was thinking, since i'm there, does anyone know of anything else I should do/ replace in that area?

That's always a dangerous question! Aux water pump/valve/hoses come to mind. If you want some more, ck the ASC pump for leaks! Ask TX

I was thinking, since i'm there, does anyone know of anything else I should do/ replace in that area?

A good time to do the Spark plugs.