Self inflation systems.

I believe they have an in line regulator to set the tire pressure... It would depend on if that regulator is a fixed or adjustable type... I would think it would be adjustable. But ive never looked that closely at ours so I'm unsure.

 

on our "newest" trailers before i had retired, we had the Hendrickson air inflation system. to be honest, we had light(er) loads than many of you guys haul. i wish i could remember the inflation we had them at, but i cannot.

i would be sure that the system can be adjusted higher or lower to what you want/need, i just personally never bothered to delve into that myself.

 

yes, ours had that as well, it is to support the rear of the trailer from dropping to the ground with the weights of the load with the fork lifts. keeping the trailers at dock level,,,,,,,i liked that part of it too.

 

I have the Hendrickson TireMaxx Pro.
Yes it can be adjusted.
There is a recommended tool to do the job correctly, about $200.
But basically there are two regulators set 15 psi apart. The back one with the knurled knob plastic cap is the minimum pressure. The front one to the left is the maximum pressure.
Every 1/4 turn of the 1/8" set screw equals 5 psi.
So if you are at 95 and want to go to 100 psi. Turn both set screws in (clockwise) 1/4 turn.

 

Hendrickson has several videos on their YouTube channel. I currently have my trailer tire air system deactivated. I want to buy the tool (Target Gauge) to eventually fix mine. Most Utility locations don’t carry the tool, but they can order it for you. There are 3 different target gauge tools, so you have to find out which tool is yours.

 

Made my own adjustment tool.
Cost under $40.00

If you open the control box, mine had directions for proper procedure to adjust.

My last trailer pressure was set at 115psi
17.5 tires.
My trailer I have now it is set at 100psi.
22.5 tires.

Good luck