View Full Version : another master cyl question

08-24-2012, 08:17 AM
I didn't want to hijack JC1's thread but I have a similar problem.

The trouble started when I pulled the right side caliper to clean it up. (car was pulling to the left when braking) I reinstalled the caliper and bled the brakes. It still pulled to the left but not as bad. I will work on that soon.

Now to the current problem. A couple of days later I got in the car and the pedal went all the way to the floor and the rear section of the resovour was dry. I thought more air in the system so I filled it up and bled all 4 wheels again. A couple more days and the same thing happened. I filled the resovour and did not ride the car. Today the resovour is dry again and there is brake fluid on the carpet.

I know the MC will need to be replaced or rebuilt. My question is if the booster might be damaged or if I need to take it off and dry it out?

Sorry for the ramble and thanks for any advice, Pete

08-24-2012, 09:24 AM
I seem to recall from many years ago, when buying/disassembling parts cars, that some had brake fluid in the booster. Seems to me that the natural "flow" of brake fluid from a leaking MC, would be down the front of the booster, and onto the engine side of the firewall. Not sure how brake fluid could possibly get inside the car, unless there is a leaking diaphragm in the brake booster. Have you noticed increased braking pressure needed or a sound of a vacuum leak from the booster. Just a couple of thoughts...

08-24-2012, 02:17 PM
airlifter, Bingo! All of the fluid you kept adding leaked into the booster. When the level got high enough inside it began to leak out the vent that is inside the car. Brake fluid will damage the rubber of the booster diaphragm. You should at least drain the unit before replacing the master cylinder. At this point you can probably postpone rebuilding or replacing the booster since it does take a bit of time for the rubber to deteriorate to the point of failure. You will know when a booster fails since more pedal effort is needed to stop the car and your engine may run rough due to the vacuum leak but in all not a big deal when the do fail. If you want to have it rebuilt there are several competent shops out there that can handle the job. Ted at TSI is one that comes to mind and also Brake Materials and Parts in Fort Wayne Indiana did a good job for me.

08-27-2012, 05:23 PM
I removed the servo today and it was full of brake fluid. I drained as much as possible. Should I go ahead and have the servo rebuilt or buy a new one? I have a new master cylinder ordered and should be here tomorrow.

Is there anything that I can spray in the servo to neutralize the brake fluid?

A new servo is over $200. How much is a good rebuild and how do they compare to new?

Thanks again

08-27-2012, 05:56 PM
When I had my servo rebuilt by Brake Materials 3 years ago the price was $150. What you get looks essentially new since it gets bead blasted and painted as well as the internals all fixed. I think TSI (Ted Schumacher) charges about the same.