Hi, this is a very common problem on right hand drive models as they could not be bothered to put a decent conversion on the clutch actuating mechanism for us people who drive on the proper side of the road.
The routing of the cable means that excessive strain is put on an already poor component [the cable tensioner, which is made of PLASTIC!! for crying out loud].
The common fix is to replace the cable and clutch pedal assembly together [about £30 all in] which is nasty job, upside down in the footwell. But you can convert the gearbox end of things to put less strain on the shoddy stuff. Using Volvo parts, however this means splitting the engine/gearbox to get at the clutch.
There are no hydraulic conversions that I know of, so your best bet is to get someone who is very mechanically minded to convert the clutch pedal to a straight pull with a proper tensioner/adjuster at the gearbox end. This is what I did and it's fine now. This does not require any new parts as such but just adapting the existing pedal and making a simple adjuster for the gearbox end of the cable [which will be much too long now].
Hope this helps.
Chris
February 2008