Weird question

I would back under the trailer, do tug test. Park, connect electrical cable, push in the red brake valve, do walk around inspection, return to landing gear handle and raise the legs. Trailer air bags deflate, which effectively raise the trailer nose, and once the trailer air bags are inflated, and if tractor air bags are inflated, it will make raising landing gear easier. However, 99.99% of OTR drivers drop trailer tooo dang high and then blame the switcher when the next driver has a hard time.

 

The tractor air bags don't deflate, what is happening is they went down because you put more weight on the tractor and they are re-leveling. Also is always best to set your parking break any time you get out of the truck, make a habit of it.

 

If bags deflate and don’t want to raise back up due to weight, you may have an air leak either bad bag or leveling valve.
Truck bags shouldn’t deflate by setting brakes, trailers can be set that way.