Clutch Behaviour

[ukbiggles]

Hi all

I was out yesterday on a run - done about 50 miles - and somewhat inconveniently got lost so pulled over to figure out where I was on the map. Having worked out my position, went to move off and the car stalled. Assumed this was just me being inept, so restarted the engine and tried again, being a little more careful about moving off. Car jumped again and stalled. Started her up again and lifted the clutch pedal really slowly and the car moved off OK. Changing gear after that didn't seem normal; the pedal seemed normal enough being depressed with the same pressure as usual against my foot, but on release it didn't seem to have the same pressure against my foot. It seemed very soft somehow although the gear changes went OK. I took the direct route home from there and about 200 yds from home had to stop at a roundabout. In trying to move off, the car jumped and stalled again. Restarted and tried to select gear, couldn't select anything. Switched off and restarted and was able to move off thought the pedal still felt 'soft' on release. Parked up at home and lifted the bonnet. Clutch master cylinder felt really hot though it was full of fluid. In fact the whole engine bay was preety hot as I had been driving it quite hard to test my cooling system.

Any suggestions what might cause this?

Cheers

Gord

[Stagdad]

Fork to Cross shaft pin sheared? A common problem by all acounts.

[ukbiggles]

Spent the last couple of hours bleeding the clutch master and slave cylinders. Trying the clutch again enabled me to give a better description of the symptoms. Sometimes the clutch behaves as normal, with the biting point about half way up the length of travel, then suddenly the biting point is almost on the floor. Would this be caused by Stagdad's suggestion?

Thanks in advance.

Gord

[Stagdad]

You could try marking the position of the cross shaft lever when depressed (the pedal not you lol) if it always moves to the same place then it must be something internal like the pin I mentioned.

[ukbiggles]

Thanks, Stagdad.

One odd thing I've noticed since bleeding the clutch is that the biting point is OK (say half way up) if I put my foot on the pedal and try to change gear. But if I am riding the clutch when moving slowly the biting point goes almost to the floor. If I then release the pedal altogether and try it again, the biting point is back to half way up. Almost like a temporary insufficiency of fluid when riding the pedal. Could this be more of a cylinder problem than a broken part?

Cheers

Gord

[flying farmer]

Sounds like your master cylinder needs a seal kit.
Sometimes the inner seal can fail so the fluid bleeds back into the reservoir when under pressure, but doesn't leak out of the main seal.
Simpler option than getting the gearbox out!

Neil

[ukbiggles]

Thanks Neil, That does sound like the simpler option!. Will investigate that

Cheers

Gord

[ukbiggles]

Neil, looks like you were right. Push rod dust cover rotten and fluid outside the cylinder. But what a job getting the clevis pin out. Some PO had fitted it the wrong way round where the split pin was to the main clutch pedal side. The clevis pin was jammed solid - wouldn't even rotate. Spent ages with wd40 and penetrating oil to release the clevis but a bu***r to work on under the dash. In the end I had to drop the steering column and remove the instrument panel to get at it more effectively. Eventually slackened off so new parts on order. Hopefully this'll fix my clutch problem

Thanks for your help

Gordon

[ukbiggles]

Hi all

New clutch master cylinder fixed this problem. Thanks to StagDad and Neil for their help.

Cheers

Gord