Trailer docking question

My question has to do with bumping the dock. When you bump the dock with the trailer and set the brakes I know the trailer will move away from the dock an inch or two after about a minute or so. Then I release the brakes and bump it back against the dock again. Sometimes the trailer doesn't pull away from the dock until it's been sitting for ten minutes or so.
Is there a way to make sure the air has bled out so I know the trailer is not going to move ? Sometimes I'll set and release two or three times to try and make sure it's not going to move, only to find out ten minutes later it moved anyway.

 

Are you talking about the air suspension control ? I usually flip the air suspension control and lower the trailer before unhooking from it.

 

The trailers I pull don't have a separate switch.

 

It still takes time for the air to bleed out. I dropped a trailer in a dock and made sure it was still butted up against it. Ten minutes later it was two inches from the dock and they were complaining about it. That's why I started looking at it a little closer.