I just replaced the clutch/flywheel/pilot bushing in my car and the clutch isn't disengaging fully.

The shop manual says the slave should extend .70" which it does not, it only extends a bit under a half inch. The pedal is very soft.

I had my son pump the pedal while I watched the master res with the cap off and the fluid is at the full line and almost doesn't move at all. We tried the pump 10 times hold and side step it method and the fluid level rises and falls an 1/8 of an inch when you do that, but other wise it sits perfectly still no matter how much you pump it. I also found it looks like a shop made their own clutch line because the u bend at the top has a pretty serious kink in it.

My question is, should the fluid be almost shooting out of the master in a full system like brakes do when you pump it? I feel like I should just replace the slave/master and line.

 

Kink in the line is most likely your problem.

 

Have you bled the clutch system?
It sounds a bit air bound start there and if it doesn't improve go onto replacement of the other parts.

 

Re: whether the fluid should move when you engage the pedal, assuming you're using slow, steady pedal movement.

It should not move much at all. Almost the very first thing that happens when you press down on the pedal is you "seal off" the hydraulics of the clutch system away from the fluid reservoir. After about the first 1/16" of master cylinder piston movement, nothing you do with the pedal should affect the reservoir level. At that point, you should be seeing slave cylinder action/displacement. Only when the pedal is near the top of the stroke and the master piston is nearly all the way back in the bore should you see any fluid movement in the reservoir.

I messed around with my '87 4+3 clutch hydraulics last year a lot, and eventually replaced the master cylinder, line, and slave cylinder. It's all working great now, and I'm getting somewhere between 0.6" and 0.7" of slave cylinder displacement from top to bottom of pedal stroke.

If you've got the gooseneck sitting above the master, like on my '87, that's a pain to bleed properly. I've used a method where you do a normal bleed from the top down, like you do brakes, and then finish up by pushing fluid up from the slave bleed port to try and get the last remaining air in the line to exit via the master/reservoir. I have no earthly idea who at GM thought that gooseneck was a good idea when it comes to getting air out of the system. It's a nightmare.

The aftermarket replacement cylinders are all China-made, and not as durable and long-lasting as the OEM cylinders, so if your cylinders are more than a few years old and you haven't been changing fluid regularly, you might have some cylinder degradation on the bores due to moisture and oxidation issues. But it sounds like you've got a line issue with the kink, also. A guy named Jim Jandik used to do cylinder rebuilds and overhauls for the original cylinders, but he's not doing that work any more. I've had some email exchanges with Jim and he is a super knowledgeable guy when it comes to C4 clutch hydraulics and the mechanical aspects of the clutch.

Step one for me was always making absolutely sure I had the air out of the system - and the gooseneck is the challenge there. Then if you are still not getting the right slave pushrod displacement, it's probably something other than air in the system - loose connections, bore degradation, seal degradation, other leaks, etc. Notice, these other problems can possibly introduce air into the system, if they are severe enough. I had a leak at the rear end of my master cylinder that was letting air in where the pushrod attaches at the rear of the M/C.

Hope this helps,
Mark Bayer
Charleston IL

 

I just took the old slave off and was pulling the master when I noticed it is indeed leaking from the back into the cabin. So that coupled with this kinked hose ill just replace all of it. I got the exedy ones which are probably crap as well but hopefully they work for a couple seasons at least!