-=Jeff=-
Well-known member
I got this directly from Bill Boudreau (www.zfdoc.com). As most of you know I have been fighting Clutch Hydraulic Issues for the last month. I went through 5 Masters and 3 slave Cylinders, The Last set being the Aftermarket Cast Units. Now the findings posted regard to the DOM (Drawn Over Mandrel) Cylinders only, Neither Bill or I have disassembled a Cast Slave yet, so we are unsure if they are an issue at this point. If my Hydraulic don’t work for very long with my cast pieces I will take the cast one apart.
So here we go:
It appears that the Seal on the piston in the slave cylinder is installed backwards. One picture below shows the correct and incorrect direction for the Seal. The second picture is a cutaway of the Slave. Bill found this on 2 BRAND NEW Slaves (from GM I believe)
I disassembled 3 Slaves I have. One purchased from The Last Detail in September of 2004, it was in a GM box. One was from Corvette America Purchased in September of 2005. The last one was purchased in May of 2006 from CARQUEST. When I disassembled the Slaves I found ALL 3 to be wrong, the seal was backwards. The GM one I had (From Sept. 2004) also had an external leak which is why I initially changed it, but kept it around for the bleeder and push rod. I contacted Bill with my finding and he will contact a person with GM. So basically this problem goes back to at least September of 2004, maybe before then.
The pictures are from Bill B. I want to thank him for helping me and letting me know what he found. He and I agreed that with my specific problem and the Slave will act as if it was good but is the seal swells it could get stuck in the bore ½ way. I even saw this on the CARQUEST slave that I got. With the Seals corrected that seem to work much better, I know neither leak so I have 2 good parts as spares, assuming the Cast unit works fine.
So here we go:
It appears that the Seal on the piston in the slave cylinder is installed backwards. One picture below shows the correct and incorrect direction for the Seal. The second picture is a cutaway of the Slave. Bill found this on 2 BRAND NEW Slaves (from GM I believe)
I disassembled 3 Slaves I have. One purchased from The Last Detail in September of 2004, it was in a GM box. One was from Corvette America Purchased in September of 2005. The last one was purchased in May of 2006 from CARQUEST. When I disassembled the Slaves I found ALL 3 to be wrong, the seal was backwards. The GM one I had (From Sept. 2004) also had an external leak which is why I initially changed it, but kept it around for the bleeder and push rod. I contacted Bill with my finding and he will contact a person with GM. So basically this problem goes back to at least September of 2004, maybe before then.
The pictures are from Bill B. I want to thank him for helping me and letting me know what he found. He and I agreed that with my specific problem and the Slave will act as if it was good but is the seal swells it could get stuck in the bore ½ way. I even saw this on the CARQUEST slave that I got. With the Seals corrected that seem to work much better, I know neither leak so I have 2 good parts as spares, assuming the Cast unit works fine.