Kazuya1274 Posted January 17, 2005 Share Posted January 17, 2005 I recently installed another CF DF clutch. I had the flywheel resurfaced. The machine shop told me that last time it was not resurfaced properly, that the outer area was suppossed to be 6 thousanths higher that the clutch surface area, and it was only 2 thousanths higher. So I had him resurface the flywheel. I also installed a steel braided clutch slave cylinder line from MSA. After installing the clutch, the TO bearing makes a noise when I depress the clutch, and the car won't go into gear (still does this, although not as bad). I concluded that the slave cylinder was leaking a little bit, and got a new OEM one from MSA. The new slave cyl. seemed to work great, so I took the car on a test drive. By the time I got back, the darn thing would grind when I tried to put it in reverse, and had trouble getting it back into 1st and 2nd. I did not replace the TO bearing this time, but it has been changed before. The last clutch install had none of these ill effects. This time, it seems like a hydraulic problem, but maybe not after putting on a new slave cylinder. Possible problems: Flywheel was resurfaced wrong, or the surface is worn down too much? I put the flywheel on wrong (since resurfacing the outer part caused me to loose my mark of where it was originally, but does it matter)? Steel braided line is doing something to inhibit clutch release? TO bearing is bad? Or, I somehow installed the clutch wrong? If I remove the transmission again, I will probably go with a Fidanza flywheel and a much stronger clutch. I wanted to do that anyways before but was trying to save money. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 17, 2005 Share Posted January 17, 2005 Check the clutch master. Most people replace both the master and the slave because they tend to go in pairs. I blew my slave out about 3 days after installing an ACT pp and I've heard others say the same so I think that part of your problem is fairly common FWIW. The other thing to check is free play in the rod that connects the pedal to the clutch master. I kinda don't think this one would cause the symptoms you're describing, but there needs to be some free play there, like 1/8" to 3/16". EDIT - One more thing. Make sure all your connections are tight and that you're not leaking anywhere. Quote Link to comment Share on other sites More sharing options...
Kazuya1274 Posted January 18, 2005 Author Share Posted January 18, 2005 Thanks for the tip. I called a local parts store and they had a master cylinder in stock for $17.99, I couldn't resist. I didn't want to get into the habit of replacing a bunch of parts, but it still sounds more and more like a hydraulic issue. Why else would the clutch work fine, only to start acting up again when my drive was over? I always thought that if the master cylinder was leaking, that fluid would run down the backside and down the firewall, but I guess it doesn't have to be that way. The seals may just be letting fluid go past them, keeping it all inside, because there are no leaks whatsoever, and the clutch fluid remains full. I'll give an update if the master cylinder change does the trick. Quote Link to comment Share on other sites More sharing options...
innerware Posted January 18, 2005 Share Posted January 18, 2005 when my master went it went slow, took weeks to fully go. Didn't leak anywhere either. After replacing master and slave everything was fine. Good luck Quote Link to comment Share on other sites More sharing options...
Kazuya1274 Posted January 24, 2005 Author Share Posted January 24, 2005 As an update, I installed a new clutch master cylinder, and this seemed to fix the problem. Although I did not take the car on a test drive yet, (too cold!) I did let it warm up and drive repeatedly back and forth, and maneuvered it back into the shop where I was doing a lot of clutch grabs in first gear. Also held the clutch down for about a minute with the transmission in reverse and first gear. I did notice that with the new master cylinder, the pedal was easier to press down. Quote Link to comment Share on other sites More sharing options...
crazy280 Posted February 14, 2005 Share Posted February 14, 2005 Hey guys I'm having a similar problem with my '73 240z, which is stock. When I bought it there was no pressure in the clutch pedal, so I had it towed home. I got underneath and saw that the slave cylinder was leaking, but nothing else, so I replaced it, and bled the system. This seemed to solve the problem, as I could now drive the car, but then I drove it for longer than a few minutes, and it resisted going into gear, and grinded going into reverse. So I figured I should replace the master cylinder, which I did this afternoon, re-bled the system, took it for a spin, but still the same problem. So then I adjusted the pedal so that the pushrod was deeper into the master cylinder. Didn't work. Tried the opposite, didn't work. I inspected my '75 280z, which works fine, and noticed the stopper on the floor was not as high up as it is on my 240z. But maybe it was just my imagination. So should I buy the older "adjustable" slave cylinder, or what? Are the lines corroded? Is the clutch spring worn? I'm dying here guys! Please help me! Thanks Quote Link to comment Share on other sites More sharing options...
bjhines Posted February 14, 2005 Share Posted February 14, 2005 Look at the procedure for setting up the clutch pedal in your service manual. I had similar problems after reassembling my 1972 a few years back. It turns out that the clutch pedal and the master cylinder rod were not set up correctly....following factory procedures for setting the clearances and pedal height worked like a charm..... as far as the machine shop saying the "resurfacing" was done incorrectly is total B.S.... I have heard this far too often from mechanics who simply did not want to admit they never had a clue how to set pedal height or free play by factory specs. 99.999999999999999% of these clutch problems are caused by half ***, ignorant attempts to set up the pedal height and free play in the system. BUY A SERVICE MANUAL......and demand that it is followed to the letter by your mechanic. Quote Link to comment Share on other sites More sharing options...
crazy280 Posted February 15, 2005 Share Posted February 15, 2005 I've got two different service manuals and I did follow the guidelines to the letter. Quote Link to comment Share on other sites More sharing options...
260DET Posted February 16, 2005 Share Posted February 16, 2005 May not be relevant here but sometimes when an upgraded clutch is used it will not disengage properly no matter. The solution is to go down in the slave cylinder ID, or up in the master cylinder ID. Some clutches seem to just need that extra bit of travel in order to disengage fully. Quote Link to comment Share on other sites More sharing options...
fl327 Posted February 16, 2005 Share Posted February 16, 2005 I had to change my slave cyl to a 85-6 200sx one with a smaller bore to get my 240mm Spec2 clutch disengaging right. Quote Link to comment Share on other sites More sharing options...
crazy280 Posted February 18, 2005 Share Posted February 18, 2005 Well, I got under the dash again today with a friend's advice and adjusted the master cylinder pushrod as far out as it would possibly go. I had to completely remove the pedal stopper, and the pedal height is now somewhere over 9.1" (in contrast the book says it should be 8.78"). I also removed the rubber pad that snaps onto the floorpan-pedal-stopper, to give the pedal some more distance. These tricks turned out to be a decent fix/band-aid for the problem. I drove it around for a while to test it and it works fine; no grinding in reverse and all other gears engage without too much trouble. My guess is that my clutch is so worn out that the master/slave cylinders are forced to pump much farther to compensate for the distance in the clutch throw. At least there's no slippage yet.... Quote Link to comment Share on other sites More sharing options...
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