Hello everyone, new to the industry and work for a school district so here I am. Pretty much all the equipment I work on is 40yrs old or older. Anyway got a call for a pass through refrigerator not keeping temperature. Temps in the box were @ 75 deg. Compressor was going, hooked up guages and found the pressures all whacked out. Low side was @ 8psi and high side @ 340psi. Compressor was really hot. My first guess was bad tx valve. Don't want to just be a parts changer. R12 system was retrofitted with 401A back in 2002. Just want to be pointed in the right direction. Any help would be greatly appreciated.
Thank You in advanced,