Tk reefer 99chevy box van

[DD92SERIES]

hello im new i got a question i got a 99 chevy box van with TK unit dont kmow the model it has one 18"fan in the box on evap and single comp that runs off the engine it is r134a.anybody knows this unit? feels like a valve is sticking on the low side and keeps prs at 35-40psi doesnt move high side builds from 200-325,when comp shuts off and low side doesnt move from there.I mostly work on tour buses units R22,R12,R134A hope u can help thanks for your time!:confused:

[abbsnowman]

I can help you.
Is the condenser fan coming on / cycling? Sounds like you have a CB. (No matter)
Is unit not cooling? I need a bit more info.
Abbs