BMW X5 (E70) Air suspension Still not pumping up

[tjamesbo]

Struggling now with this appealing for any help / advice couple of months back my sons X 5 had a dropped rear airbag so we replaced it with an Arnott one from GSF reconed to be the best quality replacement at £160 few weeks later the other side went so we did that. The Car ran fine for a few weeks then dropped again both sides blowing the compressor fuse so after some cursory leak checks at the compressor union end and replacing both the main compressor fuse and the relay (BMW ) to no avail it looked like the typical compressor scenario the bags had been leaking it gets overworked and dies so we decided to replace it so again A Compressor from GSF some £450 and was a straight replacement no fiddling . The compressor now runs when the ignition is switched on ( it didnt before ) until it either times out or reaches pressure ???? ( about 30-50 seconds ? But here is the crunch point The Rear of the car is still one its **** and doesnt rise we checked the 10mm union where the pipes exit the valve block ? at the rear of the compressor with soapy water and no leaks we then disconnected the battery for 20 mins to try a hard reset of the computer but no change we 're now at a complete loss we think its unlikely to be a leak at the pipe airbag connection as unlikely both would go at same time ( theyre push fit connections on these arnott ones no unions to tighten up ) there are three connectors into the compressor / valve block unit I'm guessing one to power the compressor , one to control the valve block , one to measure the pressure ??? We re completely flummoxed now and dont seem to be getting anywhere on the BMW forum .... HELP : and he wants to use it travelling over Christmas
Any help appreciated , thanks
Boyd