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View Full Version : Clutch slaves keep dying? SR20DET



compression
04-28-2005, 10:15 AM
Note, this is on a Datsun 510, not a 240sx, but its an SR, so I thought I would ask you guys.

When I installed my S13 SR20DET w/5 speed tranny, I put on a brand new clutch clave cylinder with m brand new ACT "street" clutch. The slave cylinder is for an S14 USDM 240sx. I went on perfectly and worked great for a while.
When all of the sudden on day, a guy was pulling my car off the dyno and the clutch slave cylinder just erupts. The car has only maybe 700 miles on the clutch/cylinder. SO we put the car on the lift and pull it off. I remove the dust boot and disassemble it, I notice that the rubber seal(the part that is inside the cylinder) is torn.
So I get a new one from Autozone for a 1995 240sx and install it, bleed it with new fluid, and I am back on the road.
Yesterday, I was under the car for something, and I notice a fluid drip from the dust cover of the clutch slave. Note, the car has only been driven about 500 miles (and about 9 months has passed) since the last clutch slave blew.
So I drain all the fluid from the clutch line and it comes out a brownish/red color, thats weird....
So it looks like this cylinder is getting ready to die too, since it is leaking.
Why am I having so many troubles with clutch slaves?
And why has my fluid gone from clear to brown/red?
Does it have something to do with the stroke of the piston not being long enough to disengage the clutch?
Any input?
In the meantime I will do some more searching and see what I can find.
thanks for the help.

pearlS13
04-28-2005, 10:55 AM
Make sure your clutch pedal is adjusted properly (the rod behind the clutch pedal). I blew a brand new slave cylinder within 10km's of driving because my clutch pedal wasn't adjusted properly.

compression
04-28-2005, 11:33 AM
will do, but the slave cylinders last a few hundred miles...I will check that out though.

asad
04-28-2005, 11:58 AM
First, I'd try using an OEM slave cylinder. I've heard bad things about parts-store hydraulics.

Also, what clutch master cylinder are you using?

Asad

JimStinksAtDorifto
04-28-2005, 12:49 PM
First, I'd try using an OEM slave cylinder. I've heard bad things about parts-store hydraulics.




Agree 100%. a local import parts store sells brand new (not rebuilt autozone/pep boys) hydraulics for cheaper than the rebuilt units. They are often made by Tokico. Rebuilt hydraulics are good for 6 months it seems.

compression
04-28-2005, 12:59 PM
I'm using the Datsun 510 clutch master, which worked fine on my previous 510 that had a KA24DE in it, no clutch slave issues at all on that one.

mbmbmb23
04-29-2005, 03:30 PM
Make sure you prime the new unit before you put it in there. You can buy a "Nismo" slave cylinder...not sure whats special about it but it may be worth a look.

-m

duncan351
04-29-2005, 09:12 PM
Make sure you prime the new unit before you put it in there. You can buy a "Nismo" slave cylinder...not sure whats special about it but it may be worth a look.

-m



Yes prime it and definetly use a new OEM one. Keep in mind the pressure in greater than stock due to the pressure plate. The sorry AZ and Orielly brand would work for stock pressure plate but not an ACT. Once you do this you shouldn't have another problem for a long time to come.

dorimaster
04-29-2005, 10:13 PM
I know that the amount of total fluid the master moves is supposed to correspond with a slave of the same proportions. I recommend you find the same master you had on the ka-powered 510, AND you get a stock slave from a ka or sr, the dealer wants way too much, and almost any one u get from an "s" chassis car is goig to be worlds better than the crap in local parts stores. I ought to know i worked at one for a few years, they have a lifetime warranty, but man you NEED it~!

Pete

compression
05-02-2005, 04:12 PM
UPDATE: Turns out that the pushrod in the slave was too short. so I made a new one out of a craftsman screwdriver shaft. problem solved. For some reason, when the clutch pedal was all the way in, the piston inside the slave cylinder was almost popping out of the body.
maybe it has to do with my HKS flywheel/ACT clutch combo....
thanks for the replies, she is running great now.