89' Corvette ZF 6 Speed Clutch Slave Cylinder

[VetteFreak101]

Got my 89' Corvette 6 years ago with 19000 miles on the clock. At about 20,000 miles the slave cylinder was replaced because it was leaking around the front seal and causing the clutch to improperly disengage. Less than 2,000 miles later the same problem is occuring with it leaking around the front seal. The leak is substantial enough to drain the clutch master cylinder. Both slave cylinders were AC Delco parts. Has anyone had slave cylinders go so quickly in their Corvette with the ZF trans? If so did you anyone find one that is more durable and lasts a lot longer. I felt that it was a little ridiculous to go so early with so few miles, but seems like there is a design flaw in them.

 

[sstearns2]

Got my 89' Corvette 6 years ago with 19000 miles on the clock. At about 20,000 miles the slave cylinder was replaced because it was leaking around the front seal and causing the clutch to improperly disengage. Less than 2,000 miles later the same problem is occuring with it leaking around the front seal. The leak is substantial enough to drain the clutch master cylinder. Both slave cylinders were AC Delco parts. Has anyone had slave cylinders go so quickly in their Corvette with the ZF trans? If so did you anyone find one that is more durable and lasts a lot longer. I felt that it was a little ridiculous to go so early with so few miles, but seems like there is a design flaw in them.

When I replaced my master and slave cylinders I disassembled each of the and found metal shavings in both bores. Also, there were some slave cylinders made in the last few years where one of the seals in the slave was installed backward. You might be able to get a rebuild kit for the slave and master.

Scott

 

[So Bay Vetter]

Are you sure it was slave? Might want to check floor insulation where master comes thru the fire wall. If it's damp, fluid is coming thru actuator seal. Between 50K and 70K miles I've changed both master and slave twice.

 

[VetteFreak101]

It is definately the slave cylinder. I replaced it yesterday and the clutch works just fine. What ended up happening to both previous cylinders is that they leak around the front seal. No rebuild kits and no geniune GM part replacement from the dealer means I found an aftermarket one. Works fine so far, but we will see. Thanks for the input.

 

[89blackvette]

Just put one in. I did take it apart and check that seal was correctly installed and checked for trash, metal shavings, etc. All was good with it. I have 47000 miles on the first one, hope this one lasts a long long long time as it was a pain in the butt to replace with exhaust and X member under my convertable. Almost made me want an automatic.

 

[89blackvette]

Here we are 2 months later and I have leaking slave cylinder again. I did take the last one apart and found no problems before instaling it. This is begining to be a pain in the butt. Makes me uncertain if I can take the car very far from home. It worked for 2,000 miles (2months) then suddenly started leaking. I will take new on apart and checkit also. Both new ones are Wagner and look to be of good quality. SUCKS

 

[sstearns2]

My 90 is having the tell tale drips under the trans now. I haven't crawled under there to look, but the resevior is down so I'm pretty sure. My slave is just over a year old with a few thousand miles on it. It seems silly that the original part lasted for almost two decades and the new one can't make it 10% of that.

Scott

 

[Hib Halverson]

There was a big run of replacement slaves for C4 ZFs which were assembled incorrecty by the supplier. No doubt some of them are still on the shelf in places.

This might be why you've run into repeated leaking slaves.

Seems I read on the zfdoc web site about the details of these defective slaves.

 

[sstearns2]

Thanks for the info. I took my slave apart, cleaned out the metal shavings and verfied the seal was installed correctly before I installed it on the car. I'm curious to pull it and see what's causing the leak.

Scott

 

[G Winter]

Thanks for the info. I took my slave apart, cleaned out the metal shavings and verfied the seal was installed correctly before I installed it on the car. I'm curious to pull it and see what's causing the leak.

Scott

Did you flush your MC before hooking the line to the slave ?
amazing how much crud develops in them.

Glenn

 

[sstearns2]

Hi Glenn,

I replaced the master at the same time as the slave.

Scott

 

[G Winter]

Hi Glenn,

I replaced the master at the same time as the slave.

Scott

Then I assume you cleaned the line.
Maybe you had the misfortune of have junk in the MC.
I put a new Wagner on my 90 over 1 1/2 yrs ago, still good.
Did not replace the master.

Glenn

 

[So Bay Vetter]

I'm with G Winter, It sounds like there were shavings in the line from a previous breakdown.

 

[G Winter]

An added note. The line cost more than the slave.

Glenn