Clutch issue

[vaultsman]

Hi,

My ‘66 3.8S has an intermittent clutch issue at the moment.

Symptoms:

1) Pedal occasionally and temporarily locks solid on the downstroke.

2) Pedal is slow to return and occasionally the drive is not immediately taken up even when very nearly at the top of its stroke.

3) When the pedal reaches the top of the return stroke, I can sometimes feel a slight bounce against my foot.

Car has now covered 63,000 miles since new on what, I’m sure, is the original clutch.

The clutch has always felt heavy since I bought the car 10 years ago, and has covered 18,000 since then.

I’ll get the car up on ramps and have a look at what’s happening with the operating rod next week…..I’m hoping this is a problem with the hydraulics but I’m probably not going to be that lucky.

I’d be interested to get the forum’s views.

Stan

[BOB67S]

Stan
I think you are right that the most likely culprit is the hydraulics. A systematic inspection is required. The clutch hose maybe perishing so
have a bright light to hand and bend the hose to expose any weakness. A braided hose will present a greater challenge but is there any evidence
of dampness from leaking fluid?
Do a forum search on "Clutch problems " e.g a post that started 1.7.2022, if you've not done so already. It goes without saying that if you do
a strip down / overhaul of the main and slave cylinder , then new clutch fluid will be required.

Good luck with it when you get stuck in. My pal's 3.4 ' S' new clutch , during a full restoration , turned out to be the wrong size clutch in the right
size box !! Numerous hours and a lot of head scratching from wise Club members was expended , trying to work out why the clutch didn't work !
Bob

[vaultsman]

Thanks Bob,

Not had a good look over the system yet......I'm waiting until a mate of mine is free to act as pedal pusher while I'm under.

I did replace the slave about 8 years ago, but I'm fairly sure the master is original so could do with some investigation anyway.

Cheers, Stan

[John Quilter]

If the rubber hose from engine compartment bulkhead to the cylinder head is original, well worth changing. Like brake hoses they can perish internally and create a sort of one way valve that prevents the fluid from rapidly returning to the master cylinder but there us often no external evidence of this situation..

[vaultsman]

Thanks John, that's a good call.

I'm hoping to get under the car over the weekend to get a plan of action.

Cheers, Stan

[NigelW]

You beat me to that answer John, yes the hoses can collapse internally and cause the symptoms displayed. Keep us informed Stan of how it is resolved.

[vaultsman]

Finally managed to get some time on the car.

Cleaned out the slave cylinder as that seemed a little sticky, but my thanks go to John and Nigel for identifying the hose at the rear of the cylinder head as a likely suspect.....couldn't probe the bore with even .030" wire.

New hose fitted, fluid replaced, and I now have a lovely light clutch action with the pushrod adjusted to get the bite where I want it.

Cheers everybody!

Stan

[cass3958]

Well done Stan. Good to have the knowledge on here to solve the problems that crop up.

[John Quilter]

As a former Jaguar Cars employee, always happy to share my knowledge/experience.