Recently on my 93 Mazda Miata 5 speed, the clutch master cylinder was empty. I hadn't driven it in about a month and everything was working when I parked it in the garage. Thinking it was a bad master cylinder I replace it along with the rubber hose that connects to the slave cylinder. I didn't see any sign of leaking fluid at that time. After bleeding the system I drove about 30 miles and parked the car with the intent to drive it the coming weekend. Again the master cylinder was empty so I rebled and drove to the coast (about 200 miles round trip). I check the master cylinder and it was full, right where I had topped it off before the trip. The next morning the master cylinder was empty once again. I have yet to find a leak at any connection although I suspect the slave cylinder is bad and intend to replace it this week. Is it possible there is cavity in the frame near the slave cylinder that is catching the leaking fluid? I do see evidence of some liquid but I attributed that to the spillover of bleeding the system. Any owners with similar experiences?

 

i would go ahead and change the slave before you go much further. i always had to change both when i changed one. it is possible for a leak to go unnoticed, but that does seem a little severe. it could, i guess, be leaking through the seals on the piston of the cylinder and into the housing. if i were you, i would look around the transmission and see if i could see some liquid there.

 

Thanks! I think I solved the problem last night. I replaced the old slave cylinder with a new unit and the rubber boot that covered the pushrod was full of fluid...pretty dirty and rusty looking. Anyway I flushed the entire system throughly and it performed great. I'm learning as I go..lol