2003 L322 TDV6 Vogue: 150k miles.
For as long as I can remember the air suspension has been very slow moving between ride height positions but now its basically inoperable. After failing to detect any audible leaks (vehicle maintains height at rest and during operation), I went to the compressor knowing these are a common failure point.
Putting a pressure gauge inline allowed me to see the reservoir was only reaching 75psi~ before the compressor cut out (read online that the pressure should be near the 150psi mark). First thought was to replace the pressure sensor in the end of the reservoir however this had no affect,
I decided to dismantle the compressor replacing the seals and piston ring. Reinstalled however still cutting out at 75psi~. Starting to run out of ideas, I hooked up my 125psi air compressor to the system, jumped in, flicked the switch and the height adjustment worked flawlessly, faster than ever.
To confirm that it was indeed the compressor for some reason still failing after a ring and seal replacement, I jumped the relay to trigger the compressor manually and had it pressurise a hose line with gauge installed and it reached 125psi before I started to get concerned about blowing the hose and turned it off.
Now I'm confused. Clearly its capable of reaching a higher pressure however its still being shut off at 75psi.. any help would be massively appreciated..