Jag MK 2 clutch pedal problem

[geeman237]

A friends Jaguar MK2 has developed a clutch issue. Last weekend we replaced the clutch slave cylinder as the old one was leaking. New one fitted, system bled, all systems go, off he went. He calls today to say the pedal sometimes only goes 2/3 of the way down and stops and gears can’t be engaged. A few hard pumps and then all is well again. This seems to only be happening when going into gear from a stop. I am suspecting it needs bleeding again, but the pedal going hard 2/3 of travel is confusing me. If there is air in the system, then usually the pedal goes soft?

[TooMany2cvs]

How old's the master, and what was the old fluid like...?

It's entirely possible that the slave died because old, damp fluid had corroded the inside of the bore - and the master's just as bad. Bleeding probably got the master's piston using more of the bore, into the manky bits, which has damaged the seals. I've had it happen before.

[E-bmw]

You need to get under it, it could be that it is catching on something, it certainly sounds like something solid is impeding its full stroke either at pedal or slave end.

[geeman237]

I have no idea on the age of the master cylinder or state of the fluid as it has all leaked out when I saw the car. I had a good look around the master cylinder and up under the clutch pedal pivot and everything was clean and dry.
I plan on getting under the car this weekend.
Hose has previously been changed to stainless braided and no apparent leak points along the hose/pipe length.
New fluid appeared clean after some short drives and pumping. Hard to tell through the small filler cap neck though.
I will report back when I've crawled under it.
Any further input welcome.

[GreenV8S]

I don't understand what 'a few hard pumps' means when the pedal is only going part way. Does it mean the pedal suddenly goes back to normal instead of getting stopped part way through the travel?

If you can get the problem to happen while the car is stationary you could crack the bleed nipple to see whether the restriction occurring at the master or slave.

[Steve_D]

GreenV8S said:

.....If you can get the problem to happen while the car is stationary you could crack the bleed nipple to see whether the restriction occurring at the master or slave.

Good call.

Steve

[chammyman]

if not jamming or corrosion.

Was it a release bearing or a carbon release block in it? The blocks as they wear can jam up/break apart.

[rev-erend]

Could be the clutch is seizing..

[geeman237]

Ok, I checked the car over today. The pedal felt very strange. It was hard to press and wasn’t returning quickly. It would pump ok sometimes then I felt it go firm but still had travel. I had been suspecting a blockage. I opened the bonnet and checked the short rubber hose (I had a “senior moment” and previously though it was a stainless braided hose, 😬). The hose had brake fluid around the crimps. I cracked open the bleed nipple on the slave cylinder and got someone to pump the pedal. Clearly some blockage in the lines as the fluid didn’t flow out well. Removed the slave cylinder and found some lumps of rubber in the female threaded port. Concluded that the rubber flex hose has collapsed inside. Removed the hose and tried to blow through it but wasn’t getting free flowing air through. So, new hose to be ordered, flush through the lines before fitting a new slave cylinder because the other one was weeping.