Hissing when clutch is disengaged

[jedwards]

Gentlemen,
Fistly, Happy Anzac Day to all, and may we never forget.

My 1953 Series 1 80" makes a hissing sound when the clutch is let out.
Am I correct is assuming that the Withdrawal Thrust Bearing is the culprit?
My 1932 Austin 7 has a similar issues many years back and replacing the Thrust Bearing resolved that hissing noise.

When I renewed the clutch, I feel that I would have replaced the Thrust bearing, simply due to may past experience with that part so was rather surprised to hear it when I resembled the engine back into the car.

Could it be anything else?

regards and thanks in advance.
Jeff in Perth, Western Australian.

[JDNSW]

The clutch thrust bearing on the Rover gearbox is inside the gearbox. This means it gets properly lubricated, and in turn is unlikely to be the problem, although it is possible. This makes a dry spigot bush the most likely culprit.

On the other hand, it is just possible that neither is making the noise, just that the mechanical clutch withdrawal mechanism, when loaded up by pushing the pedal, is transferring engine vibration to the chassis and body, bypassing the engine mounts,and hence using the body as a sounding board.

[vnx205]

I have had a clutch pedal make a surprisingly loud squeaking noise when lifting my foot off the pedal.
It might have sounded a bit like a hiss.
I can't remember which vehicle it was because it was quite along time ago. It was the spring responsible for returning the pedal that was squeaking.
It is quite quick and easy to eliminate the pedal itself as a possible source of the noise.

[1950landy]

I have had a clutch pedal make a surprisingly loud squeaking noise when lifting my foot off the pedal.
It might have sounded a bit like a hiss.
I can't remember which vehicle it was because it was quite along time ago. It was the spring responsible for returning the pedal that was squeaking.
It is quite quick and easy to eliminate the pedal itself as a possible source of the noise.

A loud squealing noise when lifting foot off the peddle is usually caused by a dry spigot bush. A hissing noise when clutch peddle is fully depressed can be that the pressure plate has not fully disengaged & still rubbing on the clutch plate, I would check the clutch adjustment.