Clutch master & slave cylinder upgrades on 1990

[Reichert]

Last week my clutch slave cylinder gave out. Poking around the forums I found a reference to the article in HotB issue #48 about replacing the master and slave cylinders, which is excellent. A few outdated part links but overall the information was very helpful.


I followed the author's advice and replaced my '90 system with the '91+ slave cylinder and braided hose (the master cylinder is identical). I bought the parts through Corvette Central who had both the master and slave in cast iron, which were pricier but are much higher quality than the stock stamped metal versions. Here are part #'s and links:

(https://www.corvettecentral.com/c4-84-96/transmission/manual-transmission/91-96-clutch-cylinder-hose-assembly-534239)
534239 91-96 Clutch Cylinder Hose Assembly (https://www.corvettecentral.com/c4-84-96/transmission/manual-transmission/91-96-clutch-cylinder-hose-assembly-534239)
534322 88-96 Clutch Master Cylinder - Cast Replacement (https://www.corvettecentral.com/c4-84-96/transmission/manual-transmission/88-96-clutch-master-cylinder-cast-replacement-534322)
534315 91-96 Clutch Slave Cylinder - Cast Replacement (https://www.corvettecentral.com/c4-84-96/transmission/manual-transmission/91-96-clutch-slave-cylinder-cast-replacement-534315)


Installation was pretty easy as far as these cars go, and it was really nice having the slave cylinder bleeder valve pointing down in my face instead of wedged up next to the floor tub (on the stock '90 version).


As a side note, it sure would be nice if there were a separate index by subject matter of tech articles printed in the newsletters .. even a sticky post with a list would be helpful. I can't imagine having done this job as well without discovering that article.

[Top Toy]

Had to replace my slave cylinder this past week too. Went with the Valeo cast iron piece from Rock Auto. Was surprised that the original was the lower quality tubular steel variety.

Having the bleeder on the bottom certainly makes it more accessible but not good for bleeding. Air sits in the top of the cylinder, not the bottom. Had to move my hydraulic line to the master cylinder around a bit to eliminate the low point and let the air bubble up thru the master cylinder.7609

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[hotrodeddy]

Is there anyplace that rebuilds the slave cylinders or is it a better choice to get the after market replacement.

[Top Toy]

Considering that the after market slaves (cast iron version) are higher quality than the originals and only cost about $50, rebuilding the originals is hardly worth it unless you're going for an NCRS award.

[hotrodeddy]

thanks for the information. I may order one from rock Auto and keep my original as the car is all original.

[-=Jeff=-]

Contact Jim Jandik for rebuilding service
powertorque@msn.com

[hotrodeddy]

Thanks Jeff.

[S.hafsmo]

I wouldn't be too fast calling the cast iron version higher quality. The tubular OEM version never fails due to inadequate metal thickness, so it's plenty strong. It's the seals that fail, and I wouldn't expect the cast iron part to last as long as an OEM.
They also rust as soon as they're mounted if you don't paint it before installing.

In my opinion, it's just a cheaper, heavyer lump, and would've preferred a rebuilt OEM.

[Rich in Panama City]

It is well known in vintage sports car circles that bleeding a hydraulic clutch only requires filling the reservoir and pumping the pedal and not using the slave bleeding nipple. When I replaced my ZR-1 clutch slave I had to pump the pedal about 30 times. Different from bleeding brakes because with the clutch hydraulics you move enough fluid back and forth to work out the bubbles.

[-=Jeff=-]

Correct Rich!! I have done both, use the bleeder to drain and flush and some bleeding, then pump to complete

[S.hafsmo]

I always fill/bleed the slave before installing. Never issues with air.

[Mystic ZR-1]

Back fill the system (from the bottom up)
using a Mitey Vac pump set up to pump, not pull a
vacuum. Minimizes pumping clutch pedal.