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Brake leak mystery

delft6

Freshman Member
Offline
I have a 1975 TR6 (and have owned it since 1983). I noticed a while back that the reservoir for the front brakes was absolutely dry. Curious. I topped it off, bled it and when I came back a week later (having not driven it) it was dry again.

There is no puddle or trail of goo under the master cylinder. There is nothing under the car or under the front wheels. Having a long list of stuff to do, I put it on the back burner.

Today I pulled off the master cylinder and the booster servo. Again, no real trail of goo... though the back side of the booster servo (inside the firewall by the driver's feet) does show some peeled paint as if there has been brake fluid here before. It doesn't particularly look new. It's not wet, greasy or sticky.

I also pulled the wheels ... nothing overly noticable at the disc, the flex hose or at any of the junctions.

Any ideas here? I guess I can plug the brake line ports on the master cylinder, set it on the bench and see if it leaks out somewhere... but I'm not entirely sure which end to tackle here.
 
If it's not in the servo, then probably underneath/in your carpet. What you describe is the good old MC rear seal leak. A pit forms around the rear seal at the rest position and the fluid leaks out. It can be repaired, or you can send it off.
 
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