Clutch Problems

[sx_coupe]

Alright, I bought my car a few months ago, ran perfectly fine for a while (92 240sx m/t coupe), so one day my clutch starts slippin, ofcourse i go "greaat..." and my clutch pedal changes feels before it does it... so i go to my mechanic and tell him about my problem, he says could be the slave, but wouldnt hurt to change the master at the same time. I got a couple hundred extra in my wallet so why not, he does the work and for a day (a cold rainy day), its all fine until the next day, in the morning i drive to school and my clutch is perfectly fine. I'm drivin back when its now like 80 degrees and before i even start the car i feel alot of resistance from the clutch (this has been so before the master and slave change). So i drive around and its all good except if i push the car a bit in a gear too high it starts slippin, and the feel of the clutch varies, but by outside temperate which is strange to me, if its hot outside, the clutch clamps almost right before the pedal is almost fully released, if its cold outside it clams before mid point. What in the world is the problem? Also i have the whole 1st gear hard to engage thing like many others seem to have, someone said it was normal but if i drive for a longer time it almost gets to a point where i cant put it into 1st. What's the problem there? Thank you.

[navysnail]

has it been bled properly, and how many miles do you have on the clutch. the thing were you cant put it in first is normal, its called first gear lockout. if your going less than 15mph, just push real hard and it will go in.

[niznos]

Sorry, I don't have the answer to the actual mechanicall problem, but I'd say take it back to the person that serviced it last. He's responsible for it since he diagnosed it and serviced it.

[sx_coupe]

Sorry I didnt mention this earlier, the whole temperature changing the clutch feel has been going on before the service, thus i was simply pointing out the fact that getting a new master and slave cylinder did absolutely nothing. I talked to the mechanic again and he's pretty clueless, but yes the bleeding was done properly, i watched him do it.

[navysnail]

he didnt forget the damper did he, that thing is a pita to bleed, many people just completely remove it. how many miles you you have on the clutch

[sx_coupe]

Yes he bled the damper as well, i am uncertain of any previous maintenance to the car. Car has 129,000 miles on it.

[sx_coupe]

Anyone else heard of anything similar, also the outside temperature can be cool but if i drive in excess of an hour non stop (car getting normally hot) the same will happen as i stated before. So temperature is affecting something, but what?

[sx_coupe]

Any supertech guys out there that have any idea?

[navysnail]

it seriously sounds like a worn out clutch

[sx_coupe]

hmm, i hope thats not it but would it work fine under cold coniditions if it was worn out?

[MyCarIsWack]

i would think its ur pressure plate prollyand prolly a worn clutch

ive replcaed my clutch 3 times and master and slave 3 timesi think i have a leak in the line somewhere but i dunno

im tired of messin with my car

its a big money pittakes all my damn money

but yea

id take it to some place with a guarantee so if it ****s upu can keep takiing it back til they get it righ

[C-Kwik]

I've seen this problem. It's an issue with the master cylinder rod adjustment. The Master Cylinder has an odd design I had never seen before. Where most of the ones I've seen pull the piston back far enough to expose the hole to the reservior, the Nissan one does not. I'm not sure if any other Manifacturers do this. But in any case, the hole to the reservior is exposed only to a cavity in the piston. The face of the piston has a valve. As far as I can tell, it's kind of a one-way valve that allows fluid into the pressurized area of the master cylinder. So as you use the pedal frequently, fluid makes its way in front of the piston eventually building up so much pressure that the clutch actls like it is constantly depressed. Where the pedal arm adjustment comes in is that inside the cavity of the piston, there is a rod. If you look at the underside of the master cylinder, you'll see what appears to be a flat head screw. This is that rod. When adjuster properly,as you release the clutch pedal, the piston moves back far enough to make contact with this rod. The one-way valve I spoke of before is opened by making contact with this rod which then equalizes pressure. So the actuation rod arm needs to be adjusted so that it allows the piston to travel back far enough to open this valve. It's a simple procedure:

Under the dash, if you follow the clutch pedal, you will see the rod that attaches to the pedal arm from the master cylinder. There is a jam nut on the rod. Loosen this with an open end wrench. Then rotate the rod to make it shorter. I don't have the pedal free play figure on hand so I can't say what it should be. You don't want the rod to be too short or it will affect the engagement point and the free play.

[MyCarIsWack]

gawd damn im lost trying to read that, but prolly the problem with my car LoL

[sx_coupe]

Kwik that sounds good but is it possible for my previous master and my new master to both be equally mis-adjusted?

[erollinc]

kwik i think you may know whats wrong with my car as well im going to try what you said tommorow ...... but heres my cars trouble......... i first bought the car and the clutch was slipping (weak pedal feel and no power but revs continuously) so i bought a exedy clucht and pressure plate and paid a well known shop in the area to install it along with a almost new transmission i had laying around..... i got the car back and the clutch was still very easy to depress but drove fine and about a day later it started to "slip " again or so it felt but the car would plain stop revving at like 3 or 4 grand and it was jumpy ( like i would be at full throttle and the car would jump as if it was engaging periodicly) the problem is only after the car is hot too....... if its cold its fine... if its hot it "slips" ... the other problem is the shop wont warranty anything they did cause i supplied my own parts... bottom line is my car is pissing me off and i want it to run good all the time..... i would greatly appreciate anyone who could help me out....

kwik..... i think i have it figured out .... im doing it tommorow before autox ..... im prayin it works

[erollinc]

ok it didnt work..... damn