Air suspension problem
 

I have a hummer h2 sut 2006 it gets low after a night and thats after installing a used air compressor and new air springs there is no leaks in the pipes and when turning the car it inflates and goes normal but even after driving it for a long distance i can notice it gets lower when stopping! Please i need help what would be the problem? and excuse my writing im not an English speaker :)

Need more information to be able to help.

Is this happening equally to both sides?

Did you replace just the air-compressor or the complete Air Suspension Unit (ASU) ? (I ask this because I believe a 2006 ASU should have "twin" compressors)

yes it has the twin ! Yes equally and i replaced the complete air suspension unit (ASU)

your leaking air out. recheck your air line connections and fittings with soapy water for bubbles. or the valves might be leaking on the used compressor.

If you've changed the ASU and the problem is still the same (?) then it's unlikely to be compressor related, either that or you are extremely unlucky.

bronxteck advice is good, having said that check the two pipe connection ports on the inlet valve for leaks, release each one and clean off any dirt - DO NOT OIL or lubricate these pipes are held in by friction!

There are only 3 ways the air springs can deflate:-

1. Controlled deflation by the ASU
2. A leaky in eithe the air spring, pipe or Inlet valve connection.
3. Faulty Inlet Valves, possibly dirt or corrosion inside, contaminated O-Rings or a crack in the valve body itself. This
   YT Video
   may be helpful - BUT ignore the commentary on silicon grease!

Also is informative.

My bet is an issue at one of the quick connects for the tubes.

The air-springs operate independently, so it might have to be both quick connects..

Thank you guys for the advices i will check and i will give you a feedback
https://cimg5.ibsrv.net/gimg/www.hum...3eb04c5ba.jpeg

Yep. Air leak somewhere on one of the fittings. I recently ran into this on mine. I used a spray bottle with some dish soap/water and started spraying all fittings and actually found a tiny leak on on the fittings on the compressor and a larger leak on the top of one of the airbags. I ended up releasing the tubes (push the metal rings in) and using a cotton swab to carefully clean the o-ring in the fitting and made sure no dirt was able to get in anywhere before re-inserting the tubes.