Bleeding clutch..

I

Ian Patmore

Well-Known Forum User
At the weekend, thought I would do a easy job...bleed the clutch. New clutch matster cylinder, slave cylinder, new metal pipe and braided hose. Got all the air out, no leaks, but the pedal still travels nearly to the floor where I then get some pressure. It looks like the pin out of the slave cylinder that pushes the clutch fork, is nearly at full reach when the clutch in not depressed and the pin is just touching the fork with no pressure....so I think the pin is too short. I take it there is a different slave cylinder when using a early 280zx 'box? Explains why there was a cut down bolt in the old slave cylinder when I took the gearbox out of the donor car all those years ago. Either make a new pin, or another new slave cylinder. Anybody come across this before.....?

Cheers
Ian
 
Ian Patmore said:
At the weekend, thought I would do a easy job...bleed the clutch. New clutch matster cylinder, slave cylinder, new metal pipe and braided hose. Got all the air out, no leaks, but the pedal still travels nearly to the floor where I then get some pressure. It looks like the pin out of the slave cylinder that pushes the clutch fork, is nearly at full reach when the clutch in not depressed and the pin is just touching the fork with no pressure....so I think the pin is too short. I take it there is a different slave cylinder when using a early 280zx 'box? Explains why there was a cut down bolt in the old slave cylinder when I took the gearbox out of the donor car all those years ago. Either make a new pin, or another new slave cylinder. Anybody come across this before.....?

Cheers
Ian
Click to expand...

Got a new 280zx slave cylinder. The pin is 70mm long. Don't know if that helps?
 
Ian, I hope you have the correct release bearing collar in:eek:.

As far as slave cylinders are concerned I can't remember having to change mine when I fitted a 280 box but it was a while ago.
 
Nigel, will get back to you on that. Rob, I queried the release bearing on here a while ago, and someone kindly gave me the correct size, which off the top of my head should be the longer one, as the 225mm clutch is thinner.

Cheers
Ian
 
my 240 had wot you described,might be a 240 slave cylinder you had in it,as you described but i could still change gear ok
 
Ian, it was me who gave you the collar. I'm a bit confused by your reply because the 240mm clutch is the 'thinner' i.e. stands less proud off the flywheel and requires the longer collar. But if you've got the long collar in you should be ok anyway.
 
As far as i know its all in the rod length:eek::eek: what i mean is, is that u should be able to push the slave cylinder back as u can push a brake caliper back when changing pads ,what i am trying to say is that hydrolic cluches are self adjusting ,the slave piston will find its position as the lining wears, if the rod is to short the piston will fall out or stop up against its retaining cir -clip and will make the pedal solid, take a look at your operating fork and make sure it has room to move for and aft, i would suggest u make an adjustable rod, to make sure and if that fails try reverse pressure bleeding
 
Rob,
Oh getting confused now (does not take much) attached thread where I originally asked. So to clarify which collar goes with which clutch? I am pretty sure the short collar came out of my 280zx (which had a 240mm clutch), and since I fitted a 225mm clutch, I fitted the longer collar that you sent me Rob. Going to have to dig out the left over collar to check exactly what went in...

Cheers
Ian


http://zclub.net/forum/showthread.php?t=10315
 
All slave cylinders are the same after the earliest 240Z type - all the way to the end of the 280ZX. My suspicion is wrong release bearing carrier for the application...
 
Some emailed me to say the 225mm clutch assembly requires the taller collar, as the clutch assembly is thinner. Therefore the 240mm clutch assembly requires the shorter collar....correct?

Pretty sure this is what I have done...looks like I might have to pull the gearbox out to check.... Oh what joy
 
on the left, for a 225mm (Z and ZX 2seaters)
on the right, for a 240mm (ZX 2+2)
the bearing is the same. just the hub differs as far as I know

butees-225-240mm.jpg


hope that it helps
 
Sylv1 said:
on the left, for a 225mm (Z and ZX 2seaters)
on the right, for a 240mm (ZX 2+2)
the bearing is the same. just the hub differs as far as I know

butees-225-240mm.jpg


hope that it helps
Click to expand...

Sorry, but that's the wrong way round. The shorter one is for the 225mm clutch.
 
you can adjust the clutch via the pedal box area as the back of the clutch master cylinder is threaded to adjust the pin that fits to the clutch pedal.
 
There are two different heights of 225mm pressure plate - one for the 240Z and most early 260Z, the other for 260Z 09/74 to 10/75. The latter is pretty rare. The 240mm pressure plate is the same height as this later 225mm - both are short by comparison the the more common 240Z 225mm clutch.

30501-A8601 for early 225mm clutch
30501-K0400 (now K0404) for the rest

K0404 I have in stock and it is what Nissan provide for late clutches and it looks like the RH version in the picture. I personally don't think it is right, but we are about to try one in the workshop in the next day or so, so will use the experience to clarify the situation here if possible as I have a feeling there is a fundamental mistake in place....
 
Nigel Brook said:
Sorry, but that's the wrong way round. The shorter one is for the 225mm clutch.
Click to expand...

I ignored the "late 225mm" so I was unprecise; the left is for 240 or early 260.

That picture is taken on the silver wing of my 240Z while swapping 225mm to 240mm.
I kept original hydraulics from 240z.

The left one is either the original one of my 240z or the one of a 2.4 Laurel Sedan (I mixed gearbox parts between the two); anyway that was working fine on my 240z (with 225mm clutch from the Laurel).
The clutch mechanism of the Laurel (I think ~77) and the 240z' one was exactly the same size.

The right one is a new one I bought from MSA when swapping to 240mm clutch from a 2+2 ZX. This clutch mechanism was very thicker, that is why the release collar hub was shorter to match the fork geometry and kynematic.

I have just checked on the gearbox that is on the floor at the moment. There is no error between the picture and my swap experience.

I didn't test long hub with 240mm or opposite... don't know how it works.

Did I make mistake?
I hope someone can confirm or not before I put back the gearbox...


Ian, I am not sure to understand if your slave cylinder is the good original one or not?

the diameter should be written on the casted body of master and slave.
That could be a good checking here.
 
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Ian, I think you had the short carrier off me by request. However I also thought that was the correct one for a 225mm clutch (opposite to Sylv1's thinking).

However reading MrF's post it seems there is a 'shallow' version of the 225mm pressure plate which requires the longer collar. Perhaps you have one of these.

At the end of the day I think you have the wrong carrier/clutch combination.

Does this help:

http://www.thezstore.com/store/merchant.mvc?Screen=CTGY&Category_Code=SCCB08

or confuse even more?
 
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Beware USA clutch specs and years applied are different to the UK.

My thoughts are long carrier for later clutches, short carrier for early, but what Nissan put in the box these days don't correspond to that...
 
Nigel Brook said:
Sorry, but that's the wrong way round. The shorter one is for the 225mm clutch.
Click to expand...

Just to clarify what I've said.
I have dismantled three working STANDARD 280ZX'S 2+2, and the long carrier is the one used in all of them (240mm clutch). I have one short carrier which came out of my working STANDARD 240z 1971. This would fall in line with Mr F's long and short pressure plates.
 
Oh?
My Z is US one & my short is from Nissan, that is probably the reason of the mistake

I have other gearbox with their hub

:confused:I ll check when back from hollydays

sorry for confusing
 
Last edited by a moderator:
Thanks all for trying to sort this out. Confused as heck, but I think, like that has been suggested, I have the wrong collar fitted.... can't with confidence now say what one is fitted, though I still think the shorter one came out of the 280zx...but this flies in the face of what is suggested here.... so out it comes so I can be sure, and I will pass what I find on....

There also maybe that since this is an aftermarket clutch, they may have made the clutch to fit the other (wrong) bearing collar.

Moggy, I knew there was adjustment at the pedal, but I felt there was something more fundamentally wrong, before adjusting there, as there would have been far too much adjustment to make.

Thanks again all
Ian
 
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