I'm posting in this section because my issue with my master cylinder came up during a track event January 11&12.

I give the car a quick once over after every session and after my next to last session on Sunday I noticed a single drip of brake fluid on the booster below the master cylinder. I wiped off the booster and went out for my last seession and took it a little easy. I checked it when I came in and there was a single drip again.

This is my daily driver and it has not lost anymore fluid in over a week. Is it possible it is coming out of the cap or do you think the seals are leaking under the intense pressures generated on a road course? I know the correct answer is to replace the master cylinder but I was curious if anyone else has run into this. Oh BTW the car only has 45,000 miles on it.

 

Could be seals, could just be plain heat. If the pressure gets high enough due to exansion the fluid has to go somewhere. Master cylinders aren't rebuilt any longer that I'm aware, they are just replaced. Previously you could be re-bore kits and the like.

New seals may be available though, I never looked.

 

I don't believe a rebuild kit is available and I'm not sure I would trust it anyway. Discount auto has new Bendix units for $103 so I'm going to go that route. Does anyone know if there is any special procedure for bleeding the ABS unit?

 

It could be leaking around the cap under pressure or heat.

Also I have heard that the cap has a small hole under the label and that if the label is disturbed that you could get a leak there also.

 

the one thing i do know about the abs unit is you shouldnt run the fluid back thru it, the only way i know of this happening is by compressing the caliper when changing pads and not openin the bleeder valve on the caliper, debris that gets caught in the micro screens inside the abs unit flush back thru the unit and cause it to malfuntion. no way to fix it when it happens, expensive replacement. hope this helps