Land Rover Repair: 1998 P38 4.0, air suspention, vehicle mechanics

Question
Hi i live in china at the moment my RR is at my home in Ireland my brother has just informed my that when he started the vehicle he heard a hiss, one side at the rear wnet down, he sais it worked for a short time but now is low, i am the Rolls Royce and Damiler engineer however air suspention i know little about, is there anything he can check, he has no knowledge of vehicle mechanics, would appreciate any input
have the happy day
sincerely Tom

Answer
Hi Tom,

Sounds like one of the airsprings has perished and the compressor can't keep up.  The airsprings are relatively simple to replace.  There are also a few fittings that may have gone bad (one at each end of the airline) and the mufflers have a habbit of developing a leak and dumping hot air on the lines to the Right Rear spring and the resivoir tank, melting right through.  

He can manually operate the system to put air to that spring and narrow down the leak:

http://www.rover-renovations.com/kb_results.asp?ID=27