who'se rebuilt their clutch master cylinder with no luck, and THEN replaced it?
 

here's the deal. my car won't go into gear (any gear while running), and I feel it is because the clutch isn't disengaging enough.

here's what I've done:
-replaced slave cylinder
-rebuilt master cylinder w/ a kit like this
http://www.mazdatrix.com/pictures/f-clutch/mastrkit.jpg

-bled the system alot.
-even put a small spacer (1/8") in the "cup" of the slave cylinder to try and give it more throw.

here's what I have:
-'93 FD
- exedy twin disc clutch
- stainless braided clutch line.

now. nothing is leaking, and the clutch pedal feel is good. it feels as if everything is working correctly. but the end result of pushing the pedal in is not enough throw to disengage the clutch discs.

if you look at the picture above of the maser cyl. rebuild kit, you will see that it does not include the "one way valve piston" and its return spring. (found on page H-12 of FD3s service manual.

my question is this: could this one way valve be screwing me over? even though the clutch pedal feels good, and the clutch fork is working (atleast some).

I'm just trying to avoid purchasing a new master cylinder and wasting the assosiated time, if I will just end up back at the same problem.

thanks for your time, let me know if you can think of any other possible problem.

If you choose to replace it here's a cheap good quality one here http://www.autopartswarehouse.com/de...QCMA39899.html

Did the problem start happening randomly out of nowhere, or did it start after replacing/fixing something?

well the car's been down for 3 years now, while I tried to fix/upgrade/modify EVERYTHING (wtf was I thinking?) so basically I was starting from scratch w/ all my mods. I just hope it isn't a a faulty exedy twin plate clutch or something, which I doubt it would be. basically, whatever is left of the original master cylinder is the only clutch related part that is original from '93 anymore, which is why I suspect it. just hoping someone would have some insight on the "one way valve" in the master cylinder. I can't picture how it would function.

I took a couple of stabs at mine and the second time it took - my car sat for years before I got to it. There's not that much going on inside as you know. The trick is to make sure the bore is nice and clean - in my case, it took a bit more honing and polishing to get rid of some of the pits. Simply replacing the seals may not do it if the bore is damaged. If you don't have any external leaks, one would suspect trapped air, but you've mentioned you bled the system a lot. I had major hydraulic issues last year, so I know how frustrating this can be.

I would bet you still have air in the system. I have found thru my countless bleeding jobs on brakes and clutches that the FD clutch system is extremely tough to get all the air out when starting with a dry system ( new slave, lines and master ). Go back and hook up your bleed bottle to the slave and have an assistant slowly pump the clutch pedal to ensure NO tiny bubbles still exist.

The one way valve is a check valve and if it fails ( leaks ) then I would predict that fluid would bypass back into the master. In this case there would be no disengagement. You claim to have partial. When the pedal is down is there pressure at the slave ?


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is the clutch fork broken?? did you hone the cylinder bores on the slve/master before stabbing the kit in there?

Sounds like an issue with your pilot bearing. If you don't line up your tranny during installation, you'll have this issue.

Had the same issue....it was the pilot bearing.

Is this a new clutch,if it is it sounds like you could have the clutch plates around the wrong way,ie trans side where the flywheel plate should be and vice versa,been there n done it.N adjust your master cylinder push rod at the clutch pedal.rix

I hope its just more air. yes when the pedal is down there is pressure at the slave. at least the clutch fork is moving some. I can only feel it through the access port, but I think the clutch fork by the slave is moving only 1/4" or so. anyone know what the throw should be there?

I am thinking of sort of reverse bleeding it now. since the master outlet hard line goes up, loops around the brake booster then goes down I'm thinking air could get trapped there. I want to hook up a syringe to the hard line on the top side, and put a hose into a brake fluid bottle at the slave cylinder, and suck it through backwards, think it could work?

this is extra frustrating since this is the only thing (forseeable) that will stop me from driving my car for the first time in 3 years! if only in the driveway. thanks for all the replies guys:icon_tup:

No, I would simply keep bleeding and pumping slowly until you see NO MORE bubbles. Even when you think they are gone, pump the pedal 10 or 15 times then go back under and check again - bubbles will be there. I had my wife pumping the pedal once for an hour ( she's pissed of course ) and alternate filling while I was under the car bleeding with a bottle. The bubbles were very small and kept coming for some time. You will know when you're done, the pedal will be solid.

Keep going. You are using a bleed bottle to catch the fluid at the slave - correct ?

The bit about the Pilot Bearing - not your problem. Now the clutch fork, ring engagement, clutch disc install....they were all installed correct - right ?


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