Will a '91 slave cylinder work on a '90? They look real close in the pictures.

Thanks,
David

 

I am in the same situation as you. The 91 slave requires a replacement of the hose from master to slave due to fitting differences on the 91 slave vs the 90 slave. The hose is available but not cheap.

 

Contact Bill at www.zfdoc.com as he is the Pro on this. The price for the line is expensive because it is a stainless braided line. I just had the slave (AC Delco) replaced on my 96 LT4. It seems the new stock from AC Delco has the seal installed correctly ( mine was). And follow the bleeding steps Bill has on his web site as it is a pain to bleed the system with out a pressure bleeder.

 

I believe that everything from a '91 will fit. Everything on my car is from a '91

 

This is correct. Whats the problem, are there no 90 slaves available?

 

They seem to be on back order everywhere.

 

RockAuto.com has good prices for AC Delco parts and they are waiting for a new shipmaent (25 days) for a 90 model AC Delco clutch slave $89.00 or so plus shipping when they come in. It seems GM has a new vendor making the slaves or the old one got their QC problems fixed. My new AC Delco slave had the seal installed correctly.

 

The "official" GM explaination is that the early zf6 slaves had the bleeder at the 11 o'clock position where you could actually bleed the system. However, when installed in the car the bleeder hit the floor so on the production line they had to break off the bleeder after it was tight. The 91 slave moved the bleeder to 6 o'clock, which makes it useless for bleeding but it don't hit the floor any more. There was a TSB issued on this.

For the 89 and 90 C4's w/zf6's just buy the 91 & up application parts. If the dealership parts guy don't look carefully at the book they will tell you that the stuff is NLA and that they don't have any parts to sell you. My local chevy store told me that. Most of the auto parts stores have books that indicate the change, I don't know why the GM books don't indicate it.

See zfdoc.com for all the skinny on the troubles with the replacement parts. Also, if you still have the OE hose and master you may want to change all the stuff. Bill Boudreau says that is the way to do it correctly. Oh, also get some GM hyd fluid, P/N 12345347, Bill says to use that stuff in place of DOT3. The OE 90/89 hose will hook up to a 91 & up slave...I did it on mine because the hose was not in stock & took a few days to arrive.


Tom

Oh, GM says the target date for the new parts to be in is July 2007.

 

Sorry if I gave the wrong info on the hose issue. The info came from the Corvette tech at my dealership in Atlanta. How foolish of me to think that they would know.

 

I just received a 'new' slave from thepartsladi eBay seller item number 150001103862

The part is painted and has chips missing from edges of the mounting plate.

Is there any way to determine if this part is new or restored?

Is there any way to determine if this part has the seal installed backwards?

The page on ZFDOC.COM shows a non-painted part in cut away with the seal on backwards but how do I safely dissassemble mine to look?

Is the only way to send it to ZFDOC and have him go over it for me? Could I send my old one to him for restoration and return this one?

Are the new spares painted or not?

TIA

 

They are supposed to be painted.

Best way to verify it's new is look for scoring marks around the bolt holes.

Best way to verify the seal is installed right is to disassemble it.

 

Doc, I've run into the same "confusion/don't know/don't care but we ain't tellin' you" issues with both of the local dealers here in town. It usually boils down to the motivation/knowledge factor in the guy behind the counter, but my patience runs thin after a couple of bad trips.

I've had great experiences with Chris May at Superior Chev in Kansas and Mark Baker at Knoefler Chev in Wisconson, if I recall correctly.

PM me for contact details.

 

No it is correct, look at it closer:


ZOOMED:



Comparison


My Original post:
http://forums.corvetteforum.com/show...ghlight=clutch

 

If you have shop air you're in like flint! If no shop air the task is a bit more of a test of creative thinking.

Take out the boot clip & boot & push rod & remove the snap ring. Apply air to "In" fitting or use your old hose and master to apply hydraulic pressure to the slave and the piston will pop out far enough for you to rock it out with your fingers.

I don't have shop air so I use an old master and my old hose and set up the system on the work bench vise and just pump till the piston pops out. It usually doesn't pop all the way so I grab my internal snap ring pliars and put the jaws into the spot where the push rod goes and expand them and rock the piston out. You have to keep good pressure from the master on the slave...so it gets a bit busy with only two hands. But take your time and it is as safe as using shop air. Resist the temtation to grab the piston with regular pliars on the out side surface, side against the bore, that will not be a good move.

Good luck!


Tom

 

I used a set of snap-ring pliers to remove the slave piston.


They're shown in this photo (the pliers pointing at the piston).
... pepboys sells them. Squeezing them causes the jaws to spread out, do this to clamp onto the ID of the depression in the piston.

 

Thanks for the excellent pictures and advice, guys.