Yesterday my clutch started acting up for the first time. As I coasted to a stop I heard a clunking noise, pedal on the floor and the car loped forward a foot or so and stopped. No stall with it in gear, clutch in, and stopped. It did this only one other time. Several times it was noisy as I started off or rolled to stop and pressed the pedal. The shifting became a little more difficult, I had to ease it into gear as it would not go as easily as it should, as if I was not depressing the pedal enough. When I got home I smelled a light burning smell.

Once on the move, no slipping and the pedal felt as it always has.

The car is an '01 coupe with 60K. The clutch is original. Thanks in advance for any suggestions to try prior to an expensive replacement.

 

Ahh more of the infamous clutch gremlins.

One of three things in gone wrong.
1. Your clutch fluid needs to be replaced. (this is more of a problem when doing high RPM shifts but should be done regularly anyway) here is a link to directions for how to do it: http://forums.corvetteforum.com/show...70&postcount=8

2. Your master cylinder has failed. This is what happened to me. I could get the clutch to stick to floor by putting a small amount of pressure on the pedal and it would slowly sink to the floor and stay there. NO amount of the bleeding or fluid changing that Ranger suggested would work.

3. Your slave is failing. Pray that this is not the problem because your going to have to drop the entire rear end to replace it.

Good luck!

 

So you think it's in the hydraulic system rather than the mechanical? That's what I was thinking also. I have done the fluid change per Ranger's post a couple months ago, I'll try that again.

No sticking at all, does this mean the master is OK? The rear end has to be dropped to change the slave? Will bleeding likely help? Sounds like a PITA to bleed without the bleeding kit. Thanks.

 

ttt

 

There really aren't many steps an owner in your situation can take.

Please state your power level. Not sure if your profile is current.

I always recommend to start with the things you can do yourself. They may fail. But, if so, you are no worse off than where you are now. And if you succeed, you'll save $$ and inconvenience.

Your symptoms are unusual ones that if not personally encountered.

But here goes. I would follow the fluid change routine prescribed here: Taking Care of Your Clutch.

Clean the cap, the diaphragm and the reservoir. I'd change the fluid no less than 10 times with the 20-30 pedal pumps in between. Suggest using two fresh cans of Prestone DOT4 Synthetic. Cheap ($2.40 each), widely available and a step up from the GM-DOT3 that's spec for your car. Suggest not using the remnants of your last fluid change.

When refilling the fluid in the reservoir go no higher than the inside "shoulder" that's mid-way up and can be felt with the finger.

Once that's complete, go for a test drive and check it out.

If after doing this, your pedal still behaves badly, report back with revised symptoms. The next steps with be more expensive and inconvenient.

When you park it for the night do so in a spot where in the morning you will see any leakage along a path from the bell housing out to the reservoir.

Also before you change the fluid the first time please take a pic of the open reservoir. Then post it to this thread.

Good luck.

Ranger

 

Thanks Ranger, I'll try your suggestions and get back to you. My profile is accurate. No leaks, I checked that already.

Here are the pics prior to doing anything.

 

LLVETTE, the fluid looks like ATE Super Blue racing. Is it?

Ranger

 

Nope, it's Prestone Dot 3 Synth. I changed it per a previous post of yours about 3 months ago.

I just changed it twice, clear, and drove it for about 10 miles, some spirited with high RPM shifts and a lot of shifts. Seems much better almost right. Still a little stiff from 2nd to 3rd. Have to release pressure on the shifter and then slide it into 3rd instead of one fast smooth move. No smell, no slip, better!

The fluid is still clear after the drive. Could I have dis-lodged some crap in the slave with the hard fast pumps of the pedal when I was changing it?

I don't drag race the car, but I do autocross and track it.

 

I am surprised by the photos blue tint to the fluid in the reservoir.

It's likely the slave is still gunked up by debris. I'd suggest switching to Prestone DOT4 Synthetic and continuing to a total of not less than 10 swaps with the pedal pumps. They will help scour the slave. I'd do them all at once or within a day or so.

At the end of the process, please check back in.

Ranger

 

OK, I'll get some more fluid tomorrow and do that. So, I should continue to change it even though it is clear? I'm much more optimistic than I was this morning. If I don't get a chance tomorrow, I'm gone for a couple of weeks, but either way I'll get back to you and follow-up, Thanks

 

I would stay at it. What you are trying to accomplish is the cleansing of the slave, dislodging on any debris deposits. The only cost is less than an hour and a couple bucks of fluid.

The stakes are can this fix be made lasting. The alternative fix costs certainly hundreds and possibly two grand.

Ranger

 

OK, my left leg is tired from pumping the clutch pedal over 300 times. I changed at least 10 times with Valvoline Synth, "exceeds Dot 3 and 4 requirements". No Prestone DOT 4. I did see some debris floating at about the 6th change.

If anything it's worse, hard to shift especially to 2nd and 3rd as if the clutch is not fully dis-engaging. There is a mild vibration/grinding noise/feel through the shifter when starting forward or reverse that is more regular than it was yesterday.

Once again, no slippage and the pedal feel is normal all through the range including the grab point.

Does this sound like the slave? If so, where is it?

 

^^^ Are you getting any eau de clutch smell along the drivers-side firewall? If the friction surfaces are dragging while the clutch is in it should produce the smell.

Ranger

 

I got a pretty strong smell when I got home on Wed when this first started, but none now.

 

So that I am clear,

On Wed's drive you were hammering the car some and got eau de clutch smell at the completion of the test.

But today the shifter is acting up and you did could not hammer the car. But also today there was/is no smell of clutch at the end of the drive.

Is that correct?

Ranger

 

Not quite. When this first started on Wed I was driving pretty tamely, my 16 yr old daughter was with me. I was in traffic and it was hot when I 1st noticed any problems. After a 1 hr drive over the mtn to get home I smelled the clutch.

I didn't notice any shifting difference until yesterday's tests and today it's more pronounced. I frequently have to release pressure on the shifter and then slide it into gear rather then 1 fluid motion. Feels like I need to double clutch to upshift. Downshifts are fine. I usually downshift aggressively, bang the throttle, sometimes double clutch, and shift. I have not smelled the clutch since Wed. More consistant noise through the shifter today when starting forward or reverse.

 

Just curious but do you have an aftermarket shifter or have you ever had your shifter temoved and replaced?

_RR

 

I have a Hurst short shifter that's been in the car for a couple of years with no problems.

 

You'll done the self-help process and it's not brought an end to the symptoms, so it's definitely not the fluid. There is a chance of air in the hydraulics; but the pedal pumps usually displace it.

Besides bad fluid or air in the hydraulics, hard shifting can be caused by a binding master cylinder, binding clutch actuator (slave), worn tranny input shaft, or bad release bearing. In conjunction with that, the noise coming from the shifter upon clutch-out in 1st and reverse may help focus the trouble shooting.

You've gotten 61K miles from a stock clutch and hydraulics. That should be some consolation. A good tech will be able to pinpoint the issue via a physical inspection. A test drive with you driving will help the tech narrow down the diagnosis in prep for the component inspection.

You will likely face a decision as to whether to replace all the hydraulic and clutch components or just the possible suspect part(s). Labor is the biggest element of the work; most would say replace it all while you're in there, if you plan on keeping the car a while.

Good luck. Let us know the final diagnosis.

Ranger

 

Thanks for your help. I've learned some and agree with your assesment. I won't get to it for a couple of weeks, but I'll post this back up when I do. If I have to take it all down, I'll replace whatever I have the cash for.

Can you recommend a clutch? I am planning (hoping) to go h/c (420 rwhp range) in the next year or so. There's been so many opinions on here about the right clutch......Greg