Odd clutch issue

[Sulzer 12LDA28C]

Hi: on Friday 17th June we went for a spin in the Stafforshire Moorlands, high up in the hills to escape the heat. On the way back through the eastern edge of Stoke where the temperature was again pretty high the clutch pedal went to the floor. I pulled over and checked the reservoir which was full. Pressed the pedal again and resistance was back to normal and drove home without any further issue. Any idea what it could be? BTW the clutch was not slipping.

 

Thanks

Steve 

Edited June 19, 2022 by Sulzer 12LDA28C
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[ctc77965o]

Only reason can be an intermittent hydraulic failure...probably slave but could be master.

[rcreweread]

Steve - It does sound like an intermittent hydraulic problem in either the master or slave cylinder. It sounds like a seal has "turned" over and then gone back again - this can happen if they go soft.

Have you replaced either of these recently and/or are they repro items, as these are not particularly reliable? Also, are you using silicone brake fluid?

If you decide to change either of these items, I have original OE parts which have been fully reconditioned by Past Parts - they are more expensive than repro parts, but will last.

I am happy to sell them on an outright basis if your existing items are repros.

Have sent you a PM - contact me if of interest

Cheers Rich 

[Andy Moltu]

If it was hydraulic failure you might expect there to be some accompanying leakage be that past the seals or blown back out of the master cylinder.

Similarly if the bearing carrier had stuck the clutch would slip or feel solid depending on where it had stuck.

If the clutch pin had sheared again problems woulf continue to cause issues disengaging.

[John L]

How old is the fluid, it may have some water/moisture in it, and that the water expanded and blew some fluid back into the reservoir, doesn't it do the same on brakes if the fluid get very hot?

John

[Sulzer 12LDA28C]

Perhaps a couple of years - when the replacement clutch master cylinder was fitted. Very rarely needs any topping up and if it does a very small amount. No obvious leaks and clutch does not slip despite the engine having substantially more power than standard.

My thanbks to to those who have responded. Will run it later this week on a cool day and see if issues recurs. If it does then maybe will go for new OEM cylinders or equivalent

Steve

 

[Andy Moltu]

On further thought could something have caught the operating lever beneath the car and pushed the lever further back in to the slave just enough that for the first pump of the pedal it simply didn't push far enough to operate the lever enough to push the release bearing onto the clutch?

 

[Sulzer 12LDA28C]

Took the car for a spin yesterday evening - about 20 miles. Nothing untowards with the clutch. Temperature muvch lower - i wonder if thsat was the issue?

Regards

Steve

 

[Footstuck]

On a fairly old VW Transporter, I had the exact same issue. It eventually resulted in no clutch disengagement.

There looked to be sufficient travel in the slave arm.

I pulled the box and changed the clutch, thinking the issue was a stuck centre plate or other clutch fault.

On installing the box it still had the same issue, which turned out to be a severely worn slave piston which was getting jammed 2/3 of the way up its travel on a wear ridge.

The piston was in a diabolical state, but not leaking at all.