I am getting ready to swap out the clutch in the vette (93) and am planning on changing out the master and slave cylinders. My question is should i go with OEM parts or are the ones from parts stores reputable. With 125K i figure its good insurance for the clutch and tranny to put new ones in. Thanks in advance for the help.

 

Honestly you know the answer to this question. Why redo the job later because you used another part. Go OEM. The OEM equipment lasted 125K why dork arround unless your planning on getting rid of the car very near term. Just my .02

 

Before you change the slave cylinder, do a search on the Forum and read some of the posts.
There has been nothing but trouble with the replacemant slaves for the past 18 months.


http://www.zfdoc.com/CHS_Actuator_Seal_Fault.htm

 

This is worth using the search tool to investigate. Especially with the slave cylinder, there's been some manufacturing issues. In the slave, some companies have been installing the seal backwards. I'm not sure GM slaves are excluded from this problem.

I also think availability is a big part of this issue.

Besides the search (include the C4 tech forum), contact Bill @ ZFDoc.com for recommended supplies on these parts!

Don't assume OEM is always best!

gp

 

WOW, so now i think im even more confused than before. So if i go with OEM should i disassemble the slave to make sure the seals are in right? And if i go OEM where should i get them from? best price?

 

Doesn't make a difference OEM or Replacement.
Open it up and check the seal no matter where you get it from.

The first GM replacement failed.
The rabestos slave failed.
Then I finally got another genuine GM slave. Opened up the brand new slave & it had the seal installed backward. After the reversing the seal its been OK since last summer.

 

Looks like we were posting at the same time!

Enilator, you can ship your slave to Bill and he will check..... Just find best price (aftermarket) and use the savings -- over OEM to send to Bill. Masters are O.K. aftermarket (they avg $100). Make sure you buy the connecting hose to complete the clutch hydraulics restore....

gp

 

Bills the man let him hunt down the part for ya.

 

If yours don't leak, leave them in. In my experience, the replacement part won't last anywhere near as long as the originals.

 

Inspect it to see if the slave is leaking. Slave is not too hard to replace later on. Also, can you still find the hose between the master and slave anymore?

 

Ordinarily you would be correct but given the state of the replacement parts' Q/C questions you should go to zfdoc.com and read up on what Bill has found about the Q/C issues for the last 3 yrs at least.

If your hyd system is functioning okay I would leave it for now because there is no proof yet that GM has resolved the Q/C issues with the primary supplier, TRW. The last Bill knew was the release date for the new corrected parts was to be late April(?) or May. And GM never admitted that there was any excessive Q/C returns.

There are two types of parts that you can use: cast master + slave or the DOM/OEM types. The DOM's have the most mfging faults, besides the slave seal in backwards. I'm not sure about the cast slave having the seal issue, I've only used one cast slave and it had the seal in correctly but it was a different seal than the seal found in the DOM/OEM type slaves. The seal had no micro-ridges and it was larger. That slave was made by Fedral-Mogul.

The DOM/OEM masters have no seal issues but have had bore run out, bore porosity, and leaking welds @ the bung issues. Oh, forgot the DOM/OEM slaves have had the bore issues also! Oh, when I say DOM/OEM, I'm referring to stuff bought @ the chevy dealer and the stuff sold by Raybestos and Wagner...DOM, Drawn Over Mandrel = DOM. That style is the OEM stuff.:o Sorry! Oh, forgot this issue, some of the DOM/OEM masters had badly formed reserviors, they leaked air where they went into the body of the cylinder!


Tom

 

Leave your old parts in place. Access to both the slave and the clutch master don't depend on removing the clutch itself, so you can replace either one later (if you have to) with no extra problems.
Just flush the system out and top up with new fluid.

Larry
code5coue

__________
I ain't easily impressed....

 

So with 125K on the clock shouldnt the micro edges be mostly gone if not all the way? And if that is the case wouldnt that drop hydraulic pressure to where it would cause problems, even ones minute enough not to notice until it turns into big problems? Maybe im just being paranoid Let me ask you all this: Has anyone rebuilt their master or slave. I called all over yesterday and found Master rebuilds but no slave rebuilds. I have rebuilt brake masters and have taken clutch masters and slaves apart before they are a very simple design. So i would guess these would be similarly as easy to rebuild. Any thoughts?

 

It either leaks, or it doesn't.

 

I would suggest that with 125k, the car may have had them replaced at sometime in the past; also, go the Bill B"s www.zfdoc.com web site, and read about the problems with the slave cylinders and which fluid to use.
Finally, DO NOT USE aftermarket parts. I did the first time, and had to replace them in less than a 18 months (6k miles).

Good Luck

 

I don't mean to hijack this post, but I have a 1988 corvette 4+3 that is in need of new master cylinder and slave for its clutch.

Are they having the same problems with the earlier corvettes parts, or is this just a problem with the ZF6?

 

The reversed seal is a ZF-specific problem. Any other problems with bore finishing, etc, are probably the same for all the crap any given manufacturer makes.