usgecko

Would really appreciate some help diagnosing a clutch problem ( if that's possible). I would like to have a better idea of what the problem might be before going to a dealer. I live in Atlanta, have only been here a year so I don't know any local reliable mechanics, and I don't have the facilities or experience to work on something complex myself.
I have a 2003 Z06, 25,000 miles, no modifications.
Problem started a few months back. I was just getting home when clutch pedal started not returning fully to the top. Got home and the fluid was low, so low I wonder if air might have got into system. I topped it up, then did ranger method getting it cleaner. Have had no drop in fluid volume since then. Problem with pedal seems worse when car is cold seems to get better when it's warmed up. Pedal also seems to return to top more frequently if I release it slower than I usually would in normal driving. Have tried using Mityvac to draw out air ( if that's the problem) a little came out, made it slightly better but problem is still there intermittently.
can I get some suggestions on what the cause might be and if I should get the dealer to try one thing before they drop the back end of the car for the slave cylinder? Anyone in North Atlanta that has experience of a good reliable mechanic please chime in.

Evil-Twin

You have a build up of clutch dust in your hydraulics. I use a quart of brake fluid, a turkey baster, and a 1/8 hose attached so its air tight.. about 6 inches long..
Suck out all of the fluid from the master cylinder. fill the turkey baster with a load of clean brake fluid. insert the hose in the little hole at the bottom, put it in as far as you can and then start to flush the system.. be carful you do not want to splash any fluid on the car so use some towels to protect your car.. You will immediately see black contaminated dust filling the bowl with the clean fluid that has magically turned black.. you have to flush this out until the flush is clear.. now fill the bowl, close the lid.. pump the clutch, and do the whole procedure a second time.. takes about 30 minutes..I do this once a year, in the spring.

00__Vette

You will have to do what Evil-Twin says often, more often depending on how aggressively you drive your car.

I do it a couple times a month, and several times during a visit to the track.

I'm going to replace my clutch and master cylinder with an aftermarket one which will eliminate this issue. I know it is an expensive fix, but the only way I know to permanently eliminate it.

Good luck!

rrwirsi

Thanks ET. When you insert the hose, do you push the fluid or such it? Sorry for the stupid question, just never did a flush before.

Bill Curlee

A ZO6 with that low miles shouldn't have any mechanical clutch issues.

Like ET stated, your hydraulic system is full of clutch dust GOOP and or some AIR!

If the fluid was LOW, I STRONGLY RECOMMEND conducting a proper system bleed/flush from under the car at the slave cylinder. Its will cost you a bit to properly BLEED/FLUSH the slave BUT, its a WHOLE LOT less than a clutch system replacement.

IF,,,,,,, that doesn't resolve the issue, I would try to replace the MASTER CYLINDER next.
Again, Its a WHOLE LOT less than clutch replacement!

DEALERSHIPS, commonly known as "STEALERSHIPS" are the last place that I would go.

Where do you live in ALANTA? I'm sure someone will be able to recommend a good Corvette Shop for you to patronize.

Bill

striper

I believe MTI is in Atlanta. They are a high performance Corvette shop that would be good for you to contact.

laurent_zo6

Never tried the Ranger Method.
When you suck out all the clutch fluid from the bowl, isn't there the possibility of air entering the system?

dauis2

I had the same problem. The Ranger method did not cure my problem. Took it to Buyavette (I-85 on the North side of Atlanta, just inside the perimeter). Turned out to be the master clutch cylinder. Had it replaced and no problems since. I would suggest you join a local Corvette Club. I have found members are very knowledgeable and it is a fun group. I joined Peach State Corvette which has its members mostly in Fayette and Coweta Counties so that is probably not convenient to you.

neutron82

I would be more worried about where the fluid went, it is a sealed system much like the brakes so if the fluid is going that low it's most likely leaking out somewhere... the fluid will get slightly lower than normal as the clutch wears just like it does when your brake pads wear down... I would take a peek under the dash and see if there is any fluid leaking inside from the clutch master cylinder, you can also shine a flashlight down under the clutch reservoir and see if the master is leaking externally, check the master to clutch line connection, and the last and worst case would be the slave... you can remove the inspection cover off the bottom of the bellhousing and get a better view of the slave and clutch assembly

Rabbitman

How far back does this hydraulic slave system go as far as model year.
This is obviously a **** poor design and I can't believe they are still using it. I never heard of people having this problem in other cars and when you ask them if they change their clutch fluid they look at you like you're crazy.
You would think GM would have seen this problem years ago and mount the slave on the outside the bell housing with some mechanical linkage to the throwout bearing like it's been done for about the last 100 or so years.
What is supposed to be the benefit of this system, I'll be damned if I see one and all I see here is somebody having trouble with it
every day on here.
I've got an old 75 MG Midget with a hydraulic clutch and I haven't touched it or added or changed the fluid in it since I've had it since 92 and I'll be damned if I'm going to now either while it's still working fine and the fluid looks like it was just changed. Of course it never gets driven and is inside always.
I just can't imagine why GM hasn't at least put a better bleeding system on these cars so you could flush the damn thing easier without having to take the transmission out of the car to put an aftermarket hose on it. They should have seen this problem after the first year and at least have added the hose by now I would think.
Somebody please tell me why this system is so good that having to change the fluid 10 times a year to keep it clean is justifiable and obviously that's what we have to do to keep it clean.
I'm new to these cars but this is ridiculous with everything else being so advanced.