Tbh I don't really know how the system is configured, but the bags won't hold air unless the supply pipe can hold air, and also back to the valve body which may be on a hard set fault.
So the supply lines should surely be fine.
I'd have thought the system would be set up in a similar fashion to it's big brother, the L322.
The tank and valve body for that is on the O/S Uk (drivers), but I believe the tank and valve body for the Sport/Disco is on the N/S (passenger).
I think you need diagnostics tbh, there more than likely is a code stored, that will hopefully lead you in the right direction., anything else is conjecture unless someone has experience an identical scenario.
Just a wee thought, the valve body will have an exhaust port, this may have a copper/bronze silencer, usually slightly conical in shape with a blunt end, if the air has got damp it could well be iced up.
Do you have a hair drier?
If you find the inclination to heat up the valve body, find your point to direct warm air but keep your body out from under the car.
