They are easily repairable.

The sealing mechanism is a spring, ball bearing, and a o ring rubber which is shaped to form a figure 8.

You will find that an accumlination of crap has worn out the o rings.

I just turned the o ring part over , gave the spring a bit of a stretch, everything a good clean and re assembled using M4 screws and nuts. Using new o rings would be better but I didnt have any at hand.

The tap now holds OK, so there is no rush to buy a new one.

They are only £18.50 here in the UK from Lings.
_________________
Russ

MC21SP