Clutch Issue

[sunnypatz]

As I was driving, when I went to press the clutch, my clutch kinda just dropped to the floor. Now it is extremely hard to press down, and I'm not really able to shift. I can get the car moving but not able to shift.

I read a few threads, and I'm going to assume its either the CMC or the slave cylinder.

I just wanted to know, which of the two could be "more" likely to go. Or can it be anything else? I checked the reservoir for the clutch fluid and it still is topped off.

Neither of the two look particulary difficult to change. Correct me if im wrong!

[DarkCaporaL]

So it's soft or hard?

If it's soft and only engages at the last 1/2 inch of the pedal it could be a leak, an air bubble, a failed master or slave. I would start by inspecting for leaks and attempting to bleed the system. Have you checked your reservoir? Sometimes this can get low and suck up a huge air bubble if you keep it low.

If it's hard and you can't press it down it can be a blocked line, loose cable or throw out bearing.

[sunnypatz]

Yeah, it engages right at the bottom! The reservoir is still topped off...

[beacher1B0]

Check Master for leaks on the firewall. Inside and Outside. It can also leak some air in without leaking fluid out.
Check Slave for leaks by pulling the rubber boot away from the slave a little. If there is fluid in the boot, your slave is leaking.
If you replace your slave, you must for your sanity bleed the clutch line at every fitting and bleeder screw starting at the master and ending procedure at the slave. Yes, every fitting. Otherwise you will have a damned of a time getting all the air out of that damn clutch loop.
Only use DOT 3 fluid. Yes, DOT 4 and 5.1 are useable. But the Master and Slave piston seals are not designed for anything but DOT 3.

[cschepp]

I'd say it's the slave.

Now a quick question related to the thread.... With the hose that comes of the cult h master in the Gtr would this play any bit of a difference if say the line had a leak or that plastic piece is broken would this mess up the clutch master?

[Ghost]

Might want to look under your car to where the clutch fork enters the bell housing, if the fork appears to be "bent" or sitting at an angle then it's possible too your pivot ball's broken... while your there you can check the slave for damage or leaks as well. I would say of the 2 the slaves most likely to wear first.

[Ghost]

Only use DOT 3 fluid. Yes, DOT 4 and 5.1 are useable. But the Master and Slave piston seals are not designed for anything but DOT 3.

Number related to the DOT rating on brake fluid is the higher the number the higher the dry boiling point. If you plan to race your car at any point got higher DOT rating. Has nothing to do with seals.

Sudenote: that's fir brakes not clutch. Brake fluid in clutch lines doesn't come anywhere near anything generating enough heat to boil it. Thought I'd clarify that. Hence steel braided brake lines and higher DOT rating on crazy race cars. Keeps the brake pressure proper without boiling fluid and melting rubber brake lines.

[sunnypatz]

Are there any DIY's on how to bleed the system?

[Ghost]

Should be able to gravity bleed like brake system. Bleeder screw is on the slave cylinder. Open valve, make sure no air bubbles coming out of valve, close and test pressure. If need get someone to slowly compress the pedal with valve open, make sure no airs spluttering out, close valve while pedals being compressed or all the way down. Make sure pedal is not let off while bleed screws open it will suck air back into the line if it's released, top off resivoir, pump pedal till feels normal pressure again. Repeat steps if needed till clutch feels proper pressure again.

[beacher1B0]

Ive bled mine twice. Went thru 2 bottles of fluid the first time and still couldnt get all the air out. Did some googling and found a thread on SAU about bleeding our clutches, because of that darn clutch loop that goes almost half of the way to the rear it is near impossible to get all the air out. Bled mine at all bleeders and fittings and it worked. The first time.
A gravity bleed would work if that clutch loop wasnt there considering it has about 4 feet of horizontal tubing and a fitting block.
All I was saying is that our Seals are designed for DOT 3, hence the raised lettering on the reservoir use DOT 3. A year from now, anything else could damage your seals. If you race, then the performance factor way outweighs the maintenace factor.

EDIT - It does not say use "DOT 3" on the CMC. My Bad.

DIY - http://www.skylinesaustralia.com/for...1#entry5778553

[rak123]

This exact same thing happened to me on my old gtst, check the clutch pedal bracket inside the car the factory one can break around the welds, take a good look to because I didn't even notice it the first time I looked under it.

[sunnypatz]

I'm going to try bleeding the system first. If that doesn't work, I'll change the slave. It was only 21 dollars at the autoparts store for a 91 pathfinder one. Might as well change it even if it's not the problem.

Should I change the CMC as well? Its only 50 bucks... I hope after changing all that it fixed the problem.

I'm not sure what to do if it is the pedal bracket nor if it's the pivot ball...any suggestions appreciated!

[Ghost]

IMO if there's no leaks you can find anywhere on the system then you should be looking at mech failure not hydraulic failure...

[sunnypatz]

So, when I went to check the slave for any leaks, I think I have ruled it out from being the problem. The slave pin basically came off without difficulty because the fork thing attached to the tranny is pretty loose. I can put the slave pin back in and out without removing the slave.

I have no technical experience, but I was told this is a major problem. Greaaaaaat.

Any ideas what it could be?

[Ghost]

Sounds like pivot ball...