Can't seem to bleed the clutch enough please help

[matpoli]

Hey guys, My Series has been out of commission for about a year now due to a noisy gearbox, $1800 later and the gearbox is back in.

I'm itching to drive it again but am having no joy bleeding the damn clutch after replacing the flexible hose and slave cylinder. My old man is a mechanic and we are both scratching our heads. We have treated it like bleeding brakes but when we finish the clutch still feels soft and has air in the line.

We can depress the clutch and put the car in gear and it's obvious that the clutch hasn't been engaged because the car won't roll. However, If we give a few quick pumps on the clutch and compress the air in the line the clutch mechanism gets extra travel and engages and the car will move backwards and forwards. Nothing that we have tried will achieve this result without the pumping.

So has anyone come across this before and if so how did you overcome it?

[JDNSW]

It is not usually a problem bleeding these. I would be looking for a mechanical problem, as the need to pump is not compressing air, but just getting more movement. If it is an early slave setup, there is an adjustment on the pushrod - see the factory manual. Later ones do not have this. Also check pedal and master cylinder pushrod adjustment.

But the most likely problem is the pins that transmit the torque from the slave cylinder bell crank to the release fork shaft. There are two of these, pinning the two shafts to the tube that joins them. My guess is that one of the pins is broken on one side or partly sheared resulting in lost motion. These pins are highly loaded and should be replaced with genuine parts or other hardened pins - mild steel bolts only last a few weeks!

John

[matpoli]

If it is an early slave setup, there is an adjustment on the pushrod - see the factory manual. Later ones do not have this. Also check pedal and master cylinder pushrod adjustment.
John

There is an adjustment on the pushrod but I thouight that adjusting it would just be a bandaid effect for the fact that we couldn't bleed it properly.

Why would it need adjusting when it was fine before, could the new slave cylinder have more travel? I'm just worried that adjusting it is cheating and a work around rather than a true fix?

[matpoli]

My guess is that one of the pins is broken on one side or partly sheared resulting in lost motion. These pins are highly loaded and should be replaced with genuine parts or other hardened pins - mild steel bolts only last a few weeks!
John

Well your guess was fairly close to what has happened but worse. When i started this project I was full of excitement but now I'm disillusioned and depressed.

The guy that reco'd the gearbox came over to assist and his first move was to disconnect the spring that went from the slave cylinder housing to the arm that holds the piston and it did give the extra travel that we needed but it just kept on traveling until it hit the front drive shaft. The coupling that the pins go into has been cracked beyond repair from pumping it constantly he said. There is no more adjustment left on the push rod so now he wants to weld it to make it longer.

I queried him as to why it all didn't just work without any stuffing around and he said it's because of the thickness of the tines or something on the pressure plate as we had that reco'd as well. So I'm wondering why the thickness is different, did he give me a different pressure plate, it did look different actually, would that make a difference? So now I need a new coupling which he is trying to source for me.

I don't want to use the clutch without the spring as the pedal was way too stiff. I thought it would just be a matter of taking parts out, putting parts back in and away we go, atm I don't want to go anywhere near my car it's just all too much, I'm just ****ing over it.

Hope you guys have a better Christmas.

[matpoli]

So...just spoke to my old man and he said that things like this aren't uncommon and even he had considered changing to a weaker spring the other day. I think i'm just a bit of a perfectionist but in the long run, as long as it works and performs as it should then modifications will be ok.

Feeling a bit better, now I'm just back to hoping that I can get it running again soon and am feeling a lot more confident.

[JDNSW]

Sounds to me a bit as if he may have used a Series 3 pressure plate. It will not work if this is what he did.

The standard S2a pressure plate uses coil springs and has three forged fingers that the release sleeve pushes against. The Series 3 pressure plate has a diaphragm spring with a large number of thin fingers that the release sleeve pushes against. The optional clutch on the 2a looks the same as this except that it has a steel ring over the release fingers, held by three tangential links of spring steel. If this is not there, there will not be enough movement to release the clutch.

The other possibility is that in overhauling the gearbox he has reassembled the clutch release shaft one spline out on the release fork.

John

[incisor]

or the toppivot pin in the pedal assembly is worn badly

i just replsced the one in madge for thst reason

[matpoli]

The other possibility is that in overhauling the gearbox he has reassembled the clutch release shaft one spline out on the release fork.
John

Hey John, man I still haven't got the old girl going. The gearbox guy wanted to heat up and bend a shaft attached to the one that goes into the slave cylinder but I wasn't happy with that.

The second option that we have taken in preference to the above was to remove the clutch plate I think and the pressure plate and have them matched together in case the clutch plate is too thick.

The third option, and the reason for the quote is that he said that something wasn't marked inside the gearbox and he may have to take the front off and move it over a spline or so. Dad said that if this was the case then the teeth should of been marked before dissassembly, is that possible.

If it was the third option then all of this stuffing around has been in vain as the issue would be with the assembly wouldn't it? Man I hope I never have to do anything to this gear box ever again after this. Anyway I'll keep this going in the hopes that something here might help anyone else who may unfortunately have the same issue one day.

Oh and incisor, I'll check that pin tonight as well just in case.

[isuzurover]

Hey John, man I still haven't got the old girl going. The gearbox guy wanted to heat up and bend a shaft attached to the one that goes into the slave cylinder but I wasn't happy with that.

The second option that we have taken in preference to the above was to remove the clutch plate I think and the pressure plate and have them matched together in case the clutch plate is too thick.

The third option, and the reason for the quote is that he said that something wasn't marked inside the gearbox and he may have to take the front off and move it over a spline or so. Dad said that if this was the case then the teeth should of been marked before dissassembly, is that possible.

If it was the third option then all of this stuffing around has been in vain as the issue would be with the assembly wouldn't it? Man I hope I never have to do anything to this gear box ever again after this. Anyway I'll keep this going in the hopes that something here might help anyone else who may unfortunately have the same issue one day.

Oh and incisor, I'll check that pin tonight as well just in case.

All of the above is gibberish and someone has been feeding you porkies. No such thing as the clutch plate being too thick and last I checked the clutch linkages were not splined.

As JD says, it sounds like a Series 3 pressure plate has been installed in a IIA box... If that is the case then things are 13mm out an no amount of fiddling will get the clutch to work.

Is it a IIA Box? (IIA clutch setup?)
Does your reconditioner have a receipt for the pressure plate which shows a part number?

This picture may help.

http://www.nhua.co.uk/Landrover/imag...s_clutches.jpg

Can you post up some pictures of the linkage positions? You are welcome to come over and check out my IIA - it has the engine out at the moment.

[Blknight.aus]

if hes put a SIII clutch pressure plate into a SII youve basically stuffed most of the mechainicals on the way though and probably damaged the throwout bearing carrier to boot.

there is a longer bearing carrier available after market and its the better solution but the center bush works just as well.

the original SII clutch has 3 metal arms not a heap of "fingers"


theres a failed one.