RebekahsZ Posted July 21, 2012 Share Posted July 21, 2012 (edited) I was "hot-lapping" at the strip last night, and by the 5th (and therefore, last) run, the clutch stopped disengaging bad enough that I could not shift from 2d to 3rd. I limped it back to the pits and hung it up for the day and put my street tires back on. Car had a while to cool off (all the drunks wanted to tell me how great my car is), such that on the drive home, the clutch was again disengaging well. I'm assuming the problem is heat. I don't know whehter the source of the heat is the clutch/pressure plate/throw-out bearing or exhaust components (I think there is plenty of clearance). Is there a heat resistant brake/hydraulic fluid I should use? I'm currently using AutoZone brand Dot 3 brake fluid. Should I have put this in the drivetrain forum? It is my LS2/T56/240z - that is why I posted here. Edited July 21, 2012 by RebekahsZ Quote Link to comment Share on other sites More sharing options...
johnc Posted July 21, 2012 Share Posted July 21, 2012 Motul RBF600. You should also make sure the clutch system is completely bled. Lots of folks do a half-assed job bleeding the clutch system. Quote Link to comment Share on other sites More sharing options...
SUNNY Z Posted July 22, 2012 Share Posted July 22, 2012 had the same issue the other night. Drove like 40 miles, got into town, and then my clutch wouldn't disengage. I was thinking of adding a heat shield as my AN line runs kinda close to the header. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted July 22, 2012 Author Share Posted July 22, 2012 Ditto. Motul fluid ordered. Quote Link to comment Share on other sites More sharing options...
SUNNY Z Posted July 25, 2012 Share Posted July 25, 2012 Turns out my slave cylinder was the culprit. It took a crap on a buddy while he was taking it to get it tinted. No bueno. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted July 25, 2012 Author Share Posted July 25, 2012 (edited) Why did your buddie want to get your slave cylinder tinted? I'm serious about getting shifting tips from you. Edited July 25, 2012 by RebekahsZ Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 25, 2012 Share Posted July 25, 2012 Might be the free play between the clutch pedal and master cylinder. I set this wrong once a long time ago and went to a track day with my BIL. Between the two of us driving the car, the clutch got hot enough that it was slipping a lot from gear to gear and finally he was complaining that it was slipping down the straights. If you set that adjustment too tight then the clutch can't release its pressure into the reservoir. The more you drive the hotter the fluid gets which causes more expansion, which partially engages the clutch, which makes it hotter and causes more expansion, etc. Catch 22. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted July 25, 2012 Author Share Posted July 25, 2012 (edited) Great idea - I had the same problem on my "drifting handbrake." Because of that, I put a permanent pressure gauge on the clutch master to ensure that it is "rigged" properly. No pressure on the master when the pedal is released and with about 3/4" slack. The Motul johnc suggested just arrived last night. Will get that swapped out Friday or Saturday. If I can get my little wiring problem sorted out, I should get to the track, maybe NEXT Thursday night and will report on whether the Motul helped or not. I may just have to bring my little cut-down open end wrench and adjust the clutch some during a night of racing...no biggie. Thanks for all the help - I love this forum. Now, can you just fix me to where I can live and work without sleep? Edited July 25, 2012 by RebekahsZ Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted July 30, 2012 Author Share Posted July 30, 2012 Sucked as much of the cheap DOT 3 brake fluid out of the clutch master with a syringe, added the Motul RBF 600 and started bleeding with my daughter on the pedal, my wife watching to make sure the reservoir didn't run dry, and me on the remote bleeder. We did get one large bubble out of the system. Unfortunately, the color of the DOT 3 and the Motul is pretty much the same, so there is no real way for me to know that I have a 100% exchange of fluid, but I ran about 1/2 bottle of the Motul thru it, so I'm hoping that between the high boiling temp of the fluid and getting that bubble out that my clutch trouble is over. I inspected the hydraulic line pathway and the line is no where near the exhaust. I think the heat is just coming from either the clutch itself, or just from under hood temperatures, but my cowl induction hood should be allowing a lot of heat to vent out. Will report back after next trip to the strip. Sure am glad I installed the remote bleeder line - made this task a snap. Quote Link to comment Share on other sites More sharing options...
SUNNY Z Posted July 30, 2012 Share Posted July 30, 2012 (edited) Not 100% related but here goes. When i took the trans out this weekend, I found that the roll pin captivated fitting on the Slave Cylinder was the problem. Now the fitting itself, which is a conversion to a male -3 fitting, but rather the side thats inside the slave. The round hole had become oval, and was allowing the fitting to shift, and fluid pass. I was able to get it warrantied from NAPA, and got it all back together. Didn't get around to driving it, because the CV boots (old ones) took a crap (new ones ordered). Edited July 31, 2012 by SUNNY Z Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted July 30, 2012 Author Share Posted July 30, 2012 SUNNY, what is the SC? Quote Link to comment Share on other sites More sharing options...
SUNNY Z Posted July 31, 2012 Share Posted July 31, 2012 SUNNY, what is the SC? fixed. thought i referenced it prior. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted July 31, 2012 Author Share Posted July 31, 2012 (edited) Sorry, I'm a moron. You moved yet? Edited July 31, 2012 by RebekahsZ Quote Link to comment Share on other sites More sharing options...
SUNNY Z Posted August 1, 2012 Share Posted August 1, 2012 Sorry, I'm a moron. You moved yet? No. I've been living out of a hotel for the last 3 weeks. I signed my lease today, and I move in tomorrow. Z is still on stands back in KS though..... It will be at least another 2 weeks before I can steal away and go back to finish it. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted August 3, 2012 Author Share Posted August 3, 2012 So I rebled clutch with Motul rbf600 drove car to work and clutch felt good. Went to track last night and on first run I couldn't shift into fourth and coasted thru traps. Limped to pits and loosened the top pedal stop and lenghthened the master cyl push rod. Ran about 10-12 more runs. Clutch functioned but it felt like it always engaged or released at a different pedal heights. Spent whole night either spinning or bogging. Spun tires at lights and got crooked enough to lift off. Spun on a 2-3 shift and almost broadsided a 70 camarillo. Ran some 7.5s but mostly 7.6s. Anybody got a good recommendation on how to adjust the clutch pedal? Same as the datsun manual says?? Gonna tear into pedals and try to get this sorted out as well as putting together the 2-step. I'm making myself look stupid at the track and getting aggravated instead of having fun. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted August 3, 2012 Author Share Posted August 3, 2012 (edited) Clutch bleeding help needed. I may have the problem figured out. I have been bleeding from under the car using a remote bleeder hose. That leaves the slave cylinder/throwout bearing at a higher location compared to my bleeder outlet. Should I elevate the bleeder outlet such that it is up-hill compared to the slave? Maybe I still don't have all the air out of it after all?? Maybe by bleeding from under the car, I am failing to get all the air out? That is my next thing to try. Thoughts? Edited August 3, 2012 by RebekahsZ Quote Link to comment Share on other sites More sharing options...
SUNNY Z Posted August 5, 2012 Share Posted August 5, 2012 I put the remote bleeder in the engine bay, and have an assistant. That way the bubbles make their way up. Almost every t56 clutch i've ever had to put in had air in the master cylinder though. You'll need a mighty-vac (available at most parts stores for around $30) put that in the hole in your reservoir, pump it up, and all the air will come out of your master cylinder. Always had great luck with this. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted August 5, 2012 Author Share Posted August 5, 2012 Sunny can you pm me your phone number again so I can call you for clarification? I agree. Even though I have bled and bled, I HAVE to have air in the system somewhere even though I did "bench bleed" the master. I want to be rippin through the gears like your video and growing as a driver. Little c r a p like this is eating me up. Quote Link to comment Share on other sites More sharing options...
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