The other day my clutch pedal only came up about 1/3 of the way, but after a few pumps it came up and has been fine since. I checked for fluid leaks at both cylinders, but everything is dry and the reservoir is still full. Is it possible for the cylinders to fail in a way that could cause issues, but not leak? I did read that some people have a bubble in their lines each spring when they bring their car out, hopefully that's the case for me.

I borrowed a friend's power bleeder, but is there anything else I can do to confirm the cylinders are good/bad?

 

The little rubber hose above the starter did this to me once. One weird day then no problem till a month later. Total fail. Cheap part but a pain to change....Bruce

 

Maybe hook up the power bleeder (empty) and pull a bit of fluid from the slave bleed nipple and see if it is blackish from seal deterioration. Check for leaks from the clutch master cylinder inside the car. Might have to pull off the rubber boot to see any fluid. If it is there, time for a new master. I did this not too long ago.

If you replace the master, suggest "reverse" bleeding instead of using the power bleeder - use gravity and air buoyancy to your advantage. The power bleeder (I have one too) works well for the brakes but not so good for the clutch. Use a pump type oil can you can get at most any auto parts store with a long-ish hose to connect it to the slave cylinder bleeder nipple - pump hose full of fluid before connecting. (a 90° elbow for the end of the hose comes in handy but not absolutely necessary; I can not recall the ID of the hose to fit the nipple so measure the nipple for a tight fit) Suck a bunch of fluid out of the reservoir (kitchen baster works well) and if it is not too old, put it in the pump can. With the pedal on the floor (reduces cylinder volume) crack the slave nipple open and pump fluid up from the slave into the reservoir (keep an eye on it for overflow). Cycle the pedal and bleed more if needed. Ensure the pedal push rod is adjusted correctly, too.

Consider replacing the slave at the same time. And "bench bleed" both of them before installing.

 

I guess I'll check the line running between the cylinders again, I already checked the interior carpet so that's not it. I could use all new fluid anyway, so I'm going to replace it all. Should I reverse bleed the clutch first, then power bleed the brakes, or the other way around? What brake fluid should I use for mostly street, but some autocross/track work? I currently have blue fluid, so I'd prefer to switch to red so I can see when I'm done replacing fluid.

 

Pentosin brake fluid (DOT 4) according to the can..is now available at AutoZone. Also available is the Pentosin Anti-freeze, and another couple of Pentosin products I can't think of right now..Anyway this might help you keep from the clutches of the Porsche (D) Stealer...