I noticed the last couple of outings the brakes getting softer and the pedal travel gradually increasing. When I opened it up I saw the front reservoir was significantly lower than before and the rear reservoir was almost gone, it looks like they've been leaking at about the same rate. If this is the master cylinder I would be very disappointed as I got it rebuilt at Karps and paid good money for it. Thoughts?


400 miles of driving.....

 

Now all you need to do is see where the leaks are.

 

Look for leaks, follow the lines, hoses, pull the wheels, unbolt and look at the back of the master cylinder. If that much fluid did go into the booster that is a problem.

 

Think we found the problem, one of the hard lines going from the master cylinder was loose. I'll know for sure later when I get it back on the road but pedal travel so far is much better.

 

Hopefully you resolved the leak. 🤞

 

Will this solve your problem? A single leaking hard line should have caused ONE of the two reservoirs to drain, not both of them. That's the whole point of a dual master cylinder system. If it's not the MC itself, you apparently should be looking for TWO leaks. You've found one. Keep looking!

 

This ^^^^^^^^^^^^

 

I did, found nothing else. What you're saying makes sense but I'm not sure where else to look, everything else checked out so far. At this point the best I I can do is get it back on the road and see which one is still dropping to narrow things down more.

 

I think that's your plan. Fill both reservoirs, drive it a bit, and see what happens to the fluid levels.

 

check under your drivers side floor mat, if the leak is up under the dash

 

If it's a bad master, and you have power brakes, it will barf on the booster. or in the booster. If you don't, it will barf on the firewall/ the floor inside the car.