I understand the TX valves are up under the dash board. Are they difficult to get to and replace?
Many thanks

 

What is a TX valve?

 

Thermostat expansion valve for the ac. If it is blocked the unit will freeze up.

 

The RAVE shows the expansion valve inside the heater assembly, up behind the dash. Seems to be one of the hardest pieces to get to on the whole truck.

 

Yes, it seems to be a complete and utter biarch of a job. I have found a very good manual online which points out the items. It might be ok. I will take some videos of the process. thank you for getting back.

 

I’m not sure what’s in these discos if it’s a capillary tube or actual txv but you can try blowing nitrogen from the low side and high side see if anything comes loose

 

Ok from searching looks like a txv with bulb etc. Unless the charge in the bulb broke causing it to close I rarely see these go bad even in refrigeration where I work.
try taking liquid line filter out and blowing nitrogen into low side see if the nitrogen comes out of the high side
what are your symptoms

 

Wish l was somewhere...where worrying about the thermal expansion valve in my A/C unit was working correctly...lol. Never made it above 22°F all week...Tuesday morning...-16°F.

 

Yeah, I have never had one go bad, lots of high mileage trucks. Why do you think it is bad?

 

Usually, if you have or have had a catasphrotic failure, compressor implosion, it's recommended to change expansion valve, receiver dryer, flush system...along with damaged compressor. Not unheard of to have to change one, expansion valve without catastrophic failure, but pretty rare occasion.