My driver's seat keeps sinking down

Are you loosing air pressure when dropping trailer. Had you just dumped your air bags?

I would assume you have a small air leak under your chair which is causing chair to lose pressure. Accelerated by you sitting on the seat.

Maybe put something heavy on the seat then air it all the way up. Shut off the truck and yoy can put your head down by the seat controls and listen.

 

switch on seat may be sticking a bit and leaking off air...thats been my experience. fiddle with switch and find the sweet spot.

 

You're losing air somewhere and it probably has nothing to do with the seat (the seat is just a symptom).

 

Well, I've woke up in the morning (more than once), started the truck and my seat was down on the floor.

All I know is that any air leak anywhere can cause it.

 

I just came for the smart-aleck comments.......None have been yet but, I have faith they will be here soon.

 

When loading or unloading the "air leak" could be the leveler valve adjusting height.
Your seat as others have mentioned.