Sudden clutch failure

[elansprint71]

Driving home from Oulton Park yesterday I suffered a sudden loss of clutch fluid and ended up on a tow rope.
On inspection it seems like the piston in the slave cylinder has been pushed right out of the cylinder, never in 30+ years of driving have I had cause to change a clutch, so this is probably the area where I know least about a car!
What are the most probable causes of this catastrophe?

There appeared to be no unusual noises when the engine was running, if the thrust bearing had come to pieces, or something similar I would have expected some kind of racket. Is it possible that the release arm has failed or come off its pivot?

Help!!!



Cheers,
Pete.

[rgh0]

Pete

It is possible for the arm to bend or break or the clip securing it to its pivot to come loose. There is also a C shaped spacer between the arm and the thrust bearing held in place by a couple of wire clips that could also come adrift. You should be able to feel if the actuating lever is excessively loose.

Before you delve into the clutch have a look at the slave cylinder.
Possible that the circlip holding the slave cylinder in place has come loose and the cylinder has moved forward.

Finally possible that the adjusting nut on the slave cylinder push rod came loose and vibrated down the rod and allowed the piston to push out.


regards
Rohan

[elansprint71]

Rohan,
Thanks for the advice; the fault is not with the slave, so it's engine out
The actuating arm appears to be in it's fully operated position and it will not go back, therefore I think it had cracked and bent.
Cheers,
Pete.

[rgh0]

Pete

I agree the arms do crack and bent and if its gone beyond normal travel and it will not return thats the most likely problem.

A real PITA to do but every time you pull the engine its quicker than the last time.

good luck

Rohan

[elansprint71]

Well, as predicted the release arm had failed at the weak point where it pivots, not only does the arm bend at this point but it has three holes in it!
How many gearchanges in the last 34 years, though?

First stop tomorrow the dreaded Chris Neil's (just down the road) but I suspect I'll finish up at Matty's place.

Cheers,
Pete.

[john.p.clegg]

Pete
Thanks for the photo.I've heard about this but not seen one before,I am (are you?) going to reinforce my arm with a little rod or bar and some welding,

P.S. if you have problems getting one give me a call as i'm sure I've one in the shed...

John

[elansprint71]

Thanks for the offer John, I've ordered one from Matty, should be here tomorrow; don't plan to reinforce but will radius the sharp edges on the holes.

CN could supply the thrust bearing & clutch plate but would have to order in the fork.

Cheers,
Pete.

[john.p.clegg]

Pete
Just dug my spare out with the intention of reinforcing it/smoothing off the edges and it seems my file is blunt or the piece is hardened....

John

[elansprint71]

John,
The new one from Matty is thicker than the old one, also it is made from 3 pieces of pressed stell very neatly welded together- it looks the business.

Unfortunately it cost ....... ?65 + VAT!

Cheers,
Pete.

[john.p.clegg]

I don't suppose you took a photo of it before you put it on?

John

[elansprint71]

John,
No! I forgot

Back on the road this afternoon, just a short drive, too knackered to go any further.

Next stop Le Mans Classic!


Cheers,
Pete.