379 A/C blowing cool, sometimes briefly cold

Hey all. My 1991 379s a/c lost its chill. I checked the freon and it was at 35, so I added a little. The a/c clutch spins like normal. My mechanic tested the system with the valves and explained to me that it wasnt balancing like it should. He said theres a blockage. He wants to replace all expansion valves, dryer, pag oil, and flush the system. Its not that I dont trust him or his word, but that seems like overkill. I found online that the txv valve could be the culprit. So I was thinking of starting there. Any advice or ideas please. Thank you.

 

The expansion valve usually gets clogged up and gets stuck, it's a relatively inexpensive part to purchase $40-50, the receiver/drier should be replaced anytime you open up the system, it's about $22.

Doing a service on your system should bring it back to the level it was previously.

 

What he said^^^^^^^^^ if it’s blowing cool but not cold and a little muggy it’s definitely the expansion valve in the sleeper. Your mechanics just trying to fix it right the first time!

 

View attachment 333549 gauges first, gauges first, gauges first.

 

dont not flush with the ac compressor lines connected. also flushing the condenser really doesn't work either. unhook lines and flush lines and evap with a ac citrus flush. replace dryer/expansion, maybe condenser

 

On a 379 pete it could be the core inside the truck needs cleaning .

 

Im contemplating running a 5000 btu window a/c unit in my cab off of my batteries. I have 4 950cca diesel batteries going to a 3500 watt inverter. All about 1.5 years old and still quite strong. I cant find any info regarding how many batteries/power I should have going to the inverter. When I did this before, the inverter would state it was too low on voltage and would turn itself off. So I was wondering if I added two batteries and tied them all together would be of any benefit. Any advice is appreciated.