Drifting rex

iTrader: (17)

Well here's the story. I bought a clutch from Autozone and tried to put it on my 12a GS. When I got the clutch in and everything back together the pedal was soft and the clutch wouldn't disengage. I replaced all the hydraulics for the clutch and still wouldn't disengage. So I put the old clutch back in and couldn't get it to disengage. I took it to a transmission shop they back bleed it and got it to disengage fine. Well I had a lift availble to try and put that new clutch back in, so I figured I'd give it another try. Well it's doing the same exact thing again, the clutch won't disengage and the pedals soft. I was wondering if you guys think that the hydraulics still have air in them or if they made a different clutch for the another model and I would have gotten the wrong clutch. I have tried bleeding the clutch by pushing the pedal, but haven't had the chance to pressure bleed it yet.

Please help!

Kentetsu

If the hydraulic system worked fine with the old clutch, and you did not introduce any air into the system when changing to the new clutch, then the new clutch is at fault. Look up the clutch on RockAuto.com and see what part number they recommend, then compare that part number to the clutch that you have now. Even though the autoparts stores only hire the very most qualified and capable people (read heavy sarcasm here), they might have sold you the wrong part. Good luck!

Drifting rex

iTrader: (17)

When I changed the clutch the rod in the slave cylinder expanded out so I had to bleed the system to get it to fit back in. I went to Rock Auto, but I don't know the part number for my clutch, but it had the sizes for the clutch disc and they were the same untill 82 and older and those were smaller. I don't understand why the pedal has hadly any pressure?

bliffle

There are only a couple reasons the pedal has no back pressure: defective pressure plate in the clutch, or air in the hydraulics, or maybe the slave pushrod doesn't meet the clutch operating lever. I vote for air in the hydraulics (altho I once mounted the slave wrong and had to redo it).

Lots of people have problems getting that hydraulic circuit properly bled.

B

Siraniko

iTrader: (13)

Provided that there is no air in the system, I would adjust the clutch slave push-rod.

31rx7

The phrase "...I replaced all the hydraulics..." is where the problem may lie. The soft pedal is generally a symptom.

After the shop bled the system, you should not have needed to undo the hydraulics before changing the clutch - just unbolt the slave from the tranny. If in fact you did not open up the hydraulic system again, then there are two possibilities: there is a leak in the hydraulics (which the shop should have caught) or there is something wrong with the clutch / pp / throwout / fork assembly.

Something you can do to double check whether it is the hydraulics or the internal clutch assembly:

Get a helper to press the clutch pedal while you look at the slave cylinder. Make sure the output rod on the slave is moving the clutch throwout bearing fork. If it is not moving the clutch fork, the problem is in the hydraulics. If it is moving the clutch fork, the problem is most likely with the clutch / PP / throwout bearing / clutch fork.

If the shop bled the hydraulics and it worked, and you did not subsequently undo any clutch hoses, and now the clutch fork isn't moving, then there is a leak in your hydraulic system somewhere. Again, the shop should have caught this when they bled the system.

Did you, in fact, replace the clutch master? When these go bad, the leak usually shows under the clutch master cyl on the firewall, usually in the engine bay but sometimes in the interior. Look for peeled paint - brake fluid is highly corrosive!

If there are no detectable leaks, and the clutch fork is not moving, there is still air in the system. The clutch master or slave may be bad, but it sounds like you replaced one or both of them. There can even be a leak in the flex hose, so replace that if you haven't.

Before taking everything apart again, make doubly sure the hydraulic system is bled properly. If the clutch master cylinder was drained of fluid, it will need a "bench bleed" before bleeding the system. Do a search on the board for this process and then bleed the entire system. Then check to see if the rod from the slave is moving the fork and go from there.

Hope this helps!

Good luck!

Drifting rex

iTrader: (17)

The slave pushrod does meet the throw out fork and it does push it about an inch. Wackyracer how do you adjust the clutch slave push rod? I replaced both the master and slave,{QUOTE}After the shop bled the system, you should not have needed to undo the hydraulics before changing the clutch - just unbolt the slave from the tranny{QUOTE} When I took the slave off the tranny the push rod expanded and I had to bleed it for the slave to fit back in. Also does anybody know if the clutch was thicker on any of the models, so I know if i could have gotten the wrong clutch.

Drifting rex

iTrader: (17)

Also, I had someone put the car in gear, but push the clutch in and I could turn the eccentric shaft pulley of the engine, so doesn't that mean that the clutch is disengaged? But when I start the car, push in the clutch, and put it in gear the shifter won't go and it slows the engine speed down.

Rogue_Wulff

Sounds like you got air back into the system.

31rx7

I agree, sounds like air into the system.

You might be able to turn the eccentric shaft with the clutch partially engaged - the equivalent of slipping the clutch. But, with the engine running at idle speed it is too much to overcome.

With a helper watching (or at least with with jack stands), jack up the car, put the car in gear, e-brake off, press the clutch in, and start the engine. If the rear wheels are turning (and I betting they will because your clutch is at least partially engaged even with the clutch pushed in), slowly apply pressure to the brake pedal to see if the engine slows. It probably will and may stall proving your clutch is not fully disengaging.

I am not sure exactly how far the rod from the clutch slave should move - my car is in storage. If I recall correctly, adjust the rod so there is less than 1/8" play in the clutch fork. Somebody on the board can check this.

I am still betting that there is air in the system. How are you bleeding it?

Siraniko

iTrader: (13)

The rod at the end of the clutch pedal. The most common name for this process is adjusting clutch play or clutch pedal height etc etc. Loosen the 12mm & 10mm nuts. then turn the rod clockwise a few turns, Start the car and shift. Do this until the clutch disengage/engage.

Drifting rex

iTrader: (17)

I thought that there might still be air in the system also, I'm bleeding it by pushing the pedal, but I'm going to try and pressure bleed it tomorrow(the car is stuck in the shop where I work on it). Wacky racer I know what your talking about now,and yes I've tried adjusting it, i's almost as far out as it will go. Just in case though, does anybody know if the clutch disk differs in thickness?

BTW thanks for all the help.

bliffle

Couple years ago I had a similar problem with a new (aftermarket, not OEM) clutch on my 85. It started after I'd been driving it a couple weeks, too. I had to start it in gear to drive and do tractor shifts. In a couple days it was OK. Damn those aftermarket clutches! Usually i get clutches from M'trix. I think maybe it was hanging up on the splines.

B

Drifting rex

iTrader: (17)

I bleed the crap out of the thing and it still does it. I used a pressure bleeder and it bleed it around 10 times with the thing. Man this is really confusing me? I must have a wrong part or something.

Drifting rex

iTrader: (17)

I'm pretty sure there is no air in the lines. I won't be able to work on the car for awhile, but I'm going to pull the tranny again and check out the clutch. Does anybody have any idea if the clutches differed in thickness in the years? I have searched and found nothing, but I will keep searching.

Drifting rex

iTrader: (17)

I FIGURED IT OUT!!!!!!!!!!!!!!!!!!!
This has really been getting on my nerves. Autozone gave me the wrong pressure plate! It was to thick and wasn't able to disengage the clutch disc. Thanks for all the help though, I'm so glad I finally got this figured out.

31rx7

We are all glad you figured it out! Sometimes - like this time - it is tough to diagnose the problem via the forum!

For our benefit, how did you determine it was the wrong pressure plate? Obviously it bolted up...

Drifting rex

iTrader: (17)

When I took it out I set it next to the old pressure plate the new one was higer and when I bolted the new one to the flywheel the fingers got really flat. I drove it back home from the shop and there is a loud clicking/knocking noise coming from under the shifter. It gets quicker the faster i go and it get louder and softer as I go over bumps. I'm almost 100% sure it's the driveshaft hitting something, but I can't figure out what? I made sure all the bolts are tight also. Man!, this car never gives up!

31rx7

Could be the universal joints are bad in the driveshaft. Did it just start doing this?

Drifting rex

iTrader: (17)

It just started making the noise when i put the tranny back in and drove it. Could I have put something in wrong?

Drifting rex

iTrader: (17)

I'm a dork, it was just the driveshaft hitting on the exhaust heat sheild.