New Job, possible issue with Trainer's truck

My trailer is air ride and had the same issue. I changed the valve I mentioned earlier, and now it instantly releases the brakes even before air bags have fully inflated. It also had touchy brakes which were fixed after the repair. Driving on snow while empty, I could barely press the brakes and the trailer would lock up and start sliding sideways. It no longer does that. I might be wrong, but the issues described sound exactly like what I was dealing with, and I don't think it's normal or safe.

 

https://www.fleetpride.com/parts/air-system/air-valves/air-valve/haldex-air-valve-kn26010

It will probably be attached to the air tank of the trailer. You can cross reference other brands from that page.

 

Haldex calls it a "trailer brake control valve". They have a .pdf somewhere that lists 3 versions of it. One is for filling the tank first, one is for releasing the brakes first, and the third is a push to connect version of one of them.