3000gt clutch prob

1992 3000gt, 2wd non turbo...simple car, however.

The clutch hydraulics seem to be acting up. After sitting it works fine but after a bit of driving the hydraulics are not returning far enough and the clutch will slip.

I can turn the bleeder on the slave cylinder and all is good for the first dozen shifts or so. I can see the slave collapse.

There is a "clutch dampener" between the master and the slave, but none of that fancy vacuum assist stuff on the AWD models.

While I have replaced the master recently, I am stumped as to what is causing this.

Any help will be great.

Bruce

I had this problem on my RX7. The slave cylinder was letting a very tiny amount of fluid past the seal. It would work for awhikle and tehn I would bleed it and then it would work for awhile. I ended up replacing the slave cylinder and everything was great!

Also, on my RX8 I had a similar problem. It turns out that the hydraulics would get hot from friction during stop and go driving. The fluid would boil and cause teh pedal to drop.

There was a tsb to fix it on teh RX8 (free of charge).

Not sue if either of those items help, but it is worth a shot on teh slave cylinder part.

It is always helpful to replace all hydraulic parts of the same system at teh same time.

Rob

Well we are out on test drive 3 right now. Clutch replace 6000 miles ago and all components seem to be well away from any excess heat source. Pedal is returning to proper height and we flushed the system totally.

No leakage past he seals and they are dead simple design. I just haven't figured out what the damper does!

Cool, he's back with good reports. We shall see!

I think the slaves on those are pretty cheap ($20 or so). I had a similar problem on an Eclipse and it burned out the clutch. They can be a pain to bleed but I start with gravity bleeding and then have a friend pump the clutch pedal while bleeding to finish it off.

If there are soft lines anywhere in the system they can collapse and trap pressure on one side just like a brake hose. Just a thought.

Loosen or remove the cruise control switch at the top of the clutch pedal travel. Problem solved.

Its a common issue on 3KGTs and 2G DSMs.

The damper just keeps you from shelling out the trans or clutch by dumping the clutch. Hot rod mod is to remove it and replace it with a piece of hard line, its unneeded and ruins the clutch feel.

Is the master cylinder pushrod adjustable, and if so, is there a wee bit of slack in the adjustment? You may be covering the port if the pushrod is adjusted too long.

I own a vr4 and the original slave cylinders are known to be defective. They issued new part numbers for the updated slave cylinder. I'd replace it with a 99 slave cylinder.

You'd be wise to join 3si.org and post in the new owners section. Everyone there is very knowledgable.

Enjoy the car :) I love them.

2 days of working well and then it stranded him at the IHOP. Cracked the bleeder and it collapsed about an inch. Still no go after a few pumps of the clutch pedal. This is a friends car and he has the rubber line and a new slave coming. Monday will be a full check and repair.

Thanks

Bruce

On my challenge eclipse the whole assembly was bad . The clutch pedal where it attached was broke or bent . So we put it down at the scrap yard . it still has the brand new clutch and slave and master . We didnt feel like pulling apart the dash to fix it .

egnorant wrote: 2 days of working well and then it stranded him at the IHOP. Cracked the bleeder and it collapsed about an inch. Still no go after a few pumps of the clutch pedal. This is a friends car and he has the rubber line and a new slave coming. Monday will be a full check and repair. Thanks Bruce

Let us know the result. I'm pretty good with these cars (Ive built an entire one) and I roam 3si all the time reading common problem threads. The slave cylinder is likely the culprit IMHO.

One simple question. When sitting at a stop, is the pedal depressed while you wait for the light to change/go again/whatever? If so, it could be heat transfer from the throwoout bearing being transferred to the slave cylinder via the clutch fork/mechanism. It may seem like a long-shot, but, it almost sounds like a heat-related problem.

Well the transmission needs to come out. Removed the slave cylinder and there is no clutch engagement. Could start the car and the wheels would barely turn and we could stop them by hand (on a lift folks!) Might be a smoked clutch, pressure plate failed or something binding. Since he bought all new parts we will be replacing all.

Thanks for the info about the damper and the other "gotchas" in this system...exactly what I was looking for.

Bruce