twentyeggs

Hey, I have a 94 corvette. I just had a Spec stage 3+ clutch put into my corvette. The shop is having a problem with the hydraulics allowing bubbles into the line. They say it builds pressure, but as soon as they let off the pedal it gets air in the system. They checked the line and they said there are no leaks in the line itself. They had a problem with the slave cylinder being blocked so they replaced it.

The only thing they can think of is the O ring is bad.

Do you guys have any thoughts? There was no preexisting problem. This gremlin is brand new.

What are some things that would cause this so we can start checking them off.

Thanks!

just joe 2

Maybe just me, but. When ever I change a clutch I change master cyl., tube, & slave cyl.
Good luck Joe

cessnaguy1965

Just got done replacing these same items on my own 94. How are they bleeding the system? This can be done by one person. I suggest either a Pheonix or Mytyvac vacuum bleeder. In my case, I kept bleeding the system through the bleeder on the slave cylinder until I saw no more air bubbles. After tightening the bleeder and making sure the resevoir was full and the cap on, I pumped the clutch pedal about 50 times and voila, a good solid, stiff clutch that works great. Just be sure that you dont suck the resevoir dry with this method. Ask me how I know this. Took me about an hour of pumping and close to 2 quarts of brake fluid, but it eventually came around.

Good luck

Paul Workman

Frustrated myself with a similar issue, I happened upon a method that worked like a charm, and avoided much of the peddle pumping. Try this...

Disconnect the slave from the bell housing, open the bleeder, and using the end of the linkage rod, drive the piston slowly into the slave cylinder.

Then, put your finger over the bleeder opening and allow the spring to push the linkage rod back out, which will draw fresh fluid from the reservoir.

Repeat as necessary to remove all the old fluid, and any air.

I don't take umbrage to replacing the master/slave, except that so much stuff comes from China, and frankly there have been too many issues with some of the clutch parts coming from there. I would suggest contacting Bill Boudreau (ZFdoc.com) or Jim Jandik (http://www.powertorquesystems.com/) for replacement parts, IF that becomes necessary (now or in the future).

Good luck!!

hcbph

I'll pass along something a former mechanic told me. First off, I have an 86 so the slave is different, and maybe the master too for all I know.
When I got it last year the clutch hydraulics started leaking so I had my mechanic change out both the master and slave cylinders. Problem he ran into was there was residual air in the system that wasn't coming out. They worked for hours and even though if you pumped the clutch several times you had a firm pedal, as soon as it sat a while, the air was still in there and caused issues with engaging the clutch.
I found a Youtube where a guy used a length of plastic tube and a tip from a bleeder kit to get the air out of the master. Well I tried it and did get some air out, but not all of it. It seemed the air was collecting in the 180 degree turn in the line coming out of the top of the master cylinder.
This former mechanic said he'd worked on several C4 Vette clutches when he was working at the Chevy dealership and had been shown a trick and passed it along. Insure the reservor is full, pump the clutch 5 or 6 times fully and hold the clutch down for about 5 minutes. Hopefully during that time, the air will work it's way up to that 180 degree bend in the line. At the end of the 5 minutes, slide your foot off the clutch and let the clutch pedal pop back on it's own. I did the process twice to be on the safe side but seemed to get all the air out of the clutch system. My Vette was in winter storage since I did it and though I've worked the clutch a time or two while in storage I didn't do anything special. I got it out the other day and the clutch was still rock solid.

It's worth a try, 5 or 10 minutes of your time and no cost. Hope it helps.

twentyeggs

Thanks guys Ill give these ideas a try

Deakins

Pump fluid through it with a Pheonix Bleeder and it will be good to go. It's a pricey tool but will be worth it once you start using it!