clutch master/slave cyl AGAIN...

[rrubel]

Been a while since I've been on here, but still plugging away at the Vette. Having problems now with an aftermarket clutch master and slave cylinder assembly that was put on a couple months ago. I've put only a couple hundred miles on the car, but one or both has failed again and I can't get in or out of gear. I haven't been able yet to jack the car up and see if it's just a hose, or if it's the whole assembly, but I know I'm out of fluid - even if I hadn't seen the diaphragm in the cylinder sucked all the way to the bottom, the large clouds of smoke from under the hood would have given it away.

So - anyone know of a GOOD master/slave brand, or GOOD hoses to use? My mechanic says the parts are discontinued by GM and he's forced to use cheap foreign stuff. My Vette apparently objects to that...

Thanks much
[RICHR]

 

[Chris Kennedy]

Hi! I am not convinced that the parts HAVE been discontinued by Gm----try GMPartsdirect.com, as I asked them about this stuff for my '89 awhile back and things were still available for the ZF. Of course, you have the Doug Nash in your '86, but check with GM Parts Direct anyway. Also, you may try contacting the "Zf doc". I am sure a word search on Google will find him (I think his name is Bill Beaudreaux---he's posted here, before, and is well known). He's extremely helpful and nice, and might be able to steer you to your parts, or provided a recommended aftermarket part.

Let us know what you find out!

Cheers,

/s/ Chris Kennedy

 

[rrubel]

Hm. GMPartsDirect.com lists it as a special-order item... which in the past has meant that it's unavailable or near-impossible to find for other things I've tried to get. Dunno...

So what usually fails on these things? Some hose that I can replace with a better one, or an internal seal that would be difficult?

Is there a place that rebuilds them? I have the last set I took off the car and could send those out for reconditioning...
[RICHR]

 

[Chris Kennedy]

Try the ZF doc for leads----generally, I have been told that rebuilding these doesn't work well, as its the bore that wears, too, not just the seal.

/s/ Chris Kennedy

 

[Louis Bartay]

Try the ZF doc for leads----generally, I have been told that rebuilding these doesn't work well, as its the bore that wears, too, not just the seal.

/s/ Chris Kennedy

Ditto, www.zfdoc.com and read the bleeding the system correctly, as this is a MUST. I bet if you do not have a leak you just need to purge the air out of the system.Good Luck and let us know how it goes.

 

[LT4man]

Call Chris May at Superior Chevy. Tell him you are from CAC. Tell him Greg from Chicago says Hi!

1-800-728-8267

I got prices from him several weeks ago. His price actually beat MAM by over $100.

On an item like this, you cannot beat OEM.

Take this advice from someone who has installed a heck of a lot of clutch assemblies & hydraulics.

Save The Wave!

 

[rrubel]

Ditto, www.zfdoc.com and read the bleeding the system correctly, as this is a MUST. I bet if you do not have a leak you just need to purge the air out of the system.Good Luck and let us know how it goes.

No, there's definitely a leak... no fluid left in the reservoir at all, and it was working fine right before.

The mechanic who put the current cylinders in is going to look at it on Monday; after that, if it needs a new set I'll be sure to get GM from Superior if they have it... I'll also check in with ZF Doc and see if he has any advice.

Thanks.
[RICHR]

 

[rkew]

Discontinuation

I had the same experience as Chris on the clutch hose for my '91 ZF. Everybody said it was discontinued but when I called my local Chevy dealer they were able to order from the regional warehouse (took a day). For that part, the price wasn't any more at the dealer than it was at GMPartsDirect, but that sure wasn't the case with everything else I had to order for a clutch replacement (flywheel, clutch, pressure plate, etc.). The local dealer prices were much higher than GMPartsDirect, even after shipping.

 

[Louis Bartay]

I had the same experience as Chris on the clutch hose for my '91 ZF. Everybody said it was discontinued but when I called my local Chevy dealer they were able to order from the regional warehouse (took a day). For that part, the price wasn't any more at the dealer than it was at GMPartsDirect, but that sure wasn't the case with everything else I had to order for a clutch replacement (flywheel, clutch, pressure plate, etc.). The local dealer prices were much higher than GMPartsDirect, even after shipping.

I just had my flywheel and clutch replaced $2000.00 parts and labor. The duelmass flywheel was $1000.00. But after 72,000 miles of me playing with Mustangs, etc not bad for a stock clutch.

 

[rrubel]

I sent an email to ZF Doc and this is his response:

"Consider the possibility that the parts are coming from production run
source which has an inordinately high failure rate number as well.
Similar in design to your application, the C4 MN6 community is/was
experiencing more new failed units over the past year due to a problematic
production run of master and slave cylinders recently. I'd guess that it was
as bad as 25% failure rate (of new parts) at the worst point. This
particular type of spare part(s) infrastructure has little to no quality
assurance program in place to keep them in check. Installing a heat shield
is good and once you get a good unit installed and should provide protection
for the actuator. The only sound advice that I can give you on this one is
to be patient, keep your receipts for warrantee purposes and perceiver
through the situation.

Just as a suggestion, try using a high performance brake fluid like Super
Blue or Motul(sp?) as well. This will likely provide added protection
between the piston seal-to-cylinder wall contact surfaces."

In some ways, it's good to know that this has been a big issue lately. Wonder what my chances are of getting a decent part this time...

FWIW, my mechanic says the slave is definitely leaking, and so is the line between the two, but he was surprised that the fluid left so quickly - the leaks didn't seem that bad.

[RICHR]

 

[vettef6]

I bet it's not the slave!! It's probably just the hose that connects to the master cylinder! The fluid runs downwards along the hose and then it looks like the slave is leaking. This exact problem I had just 5 days ago. The leak was minimal but only took like 30 min. street driving to empty the reservoir.

Arnold