This has me kind of stumped and I don't have the time right now to pull off the cylinders and check. Hopefully someone has run into this before.

In city driving yesterday, the clutch pedal started resting lower and lower, as if I had a slave leak. I limped the car to a side street in first gear, then I reached down and pulled the pedal up manually.

I've been here before, bad slave cylinder or MC. But here's the thing; I can't get the symptom to repeat and I can't diagnose which cylinder is bad. The clutch pedal feels perfect no matter how many times I pump it. There isn't a noticable amount of fluid missing from the resevoir and there is no fluid leaking under the car from the slave or inside from the MC.

Don't think it's gonna be the fork. I have an OEM exedy clutch and like I said it feels fine now. I would think slave leaking into the bellhousing, but I've never seen one fix itself for this long! This sucks because I just got a set of Dunlop Z1 Star Specs on the car and was hoping to break them in.

 

If you're not losing fluid externally, it's probably the master cylinder. I've seen master cylinders that will work fine, but after you cruise and don't use them for a while you'll have a hard time building line pressure. Basically the internal seals are failing and bypassing pressure.

If the slave fails, it will typically have an external leak. There's just one seal on the slave piston, and if that goes, it leaks into the boot covering the rod.

Dale

 

Usually you want to replace the master and slave at the same time because they both tend to fail within a short period of time

 

You're absolutely right. I'm just bein lazy and cheap. In this case, my thought is that because of the slaves location it is exposed to more moisture. Slave is on the way; may listen to your advice and get a master too.

 

Odd... took off the slave and it is completely dry inside the boot. Clutch still actuates perfectly. Possible the master is bypassing internally? Relief valve sticking open?

I"m just gonna ride it out. If it happens again I'll do the master and slave.

On a side note, I do appreciate the design feature that makes it seemingly impossible to insert the slave with the pushrod misaligned with the fork. That can be a real pain on some cars.