air suspension

Check the height sensors before you look at the pump. Much cheaper to fix, and known to fail.

y and up it came but when i turned the engine off it dropped straight away c= an not hear a leak and it stayed up while engine was running do you think th= e pump has had it and if so is it hard to change one please any ideas

it might be the relay...

So it didn't come up when the engine started only after you "wiggled the relay". Which relay?

How fast does it decend? Hours, minutes? The exhaust valves in the compressor box will drop it in a few tens of seconds but you can hear them.

If the compressor is working a lot it soon will be knackered. They have a reputation for not lasting long once the system develops a leak that shows itself with a lowered suspension. They ain't cheap so try and find the cause. Could be a wiring or relay problem and the height sensors have already been sugested. Google back within the last year (maybe two) for a thread about replacing the height sensors. In theory it requires testbook and some spacers to recalibrate the computer.