2012 Cascadia a/c gets warmer after 2 hours.

Frost on the line going to the drier would indicate a blockage....was it changed when you replaced condenser/compressor?

 

It’s not blockage most likely the freeze switch in the cab is not telling the compressor to shut off or cycle and if it doesn’t cycle on and off the only thing that will happen is it’s going to freeze system starting with evaporator. I would check where the freeze switch is and replace that before putting any more $$$$ into it. Should be mounted on evaporator Assy

 

I had a similar issue to yours, and it was a costly nightmare to fix. Turned out to be a temp sensor, freightliner price 10$. It's located in the hvac box behind the cover on the passenger side and is located just to the right of the fan motor. There are 2 thin wires into a small connector, if you unplug it you can pull it out . Sort of like a plastic frame about 3 inches long and 3/8 wide. It might not be that, but it's the cheapest part I've bought for my truck and it worked for me.

 

When I see an A/C freeze up, the first thing I do is remove the fan motor and wash out the evaporator with water (garden hose adapted to a 1/4 air line) fixes the issue 90% of the time. But our trucks run about 80% off road and the filters just don’t catch all the dust.