I had a bad burn this summer on a trane HP and got handed a one way drier and said....hey this ain't right.
Trane said its correct we want drier back in oem spot before OD txv. I say ok and took drier put in back of van.
Guess they didn't think it would be a problem to not run freon through drier until winter.
I installed suction line hh core and liquid hh cord biflow and oil was still slightly acidic after 2-3 hrs but came up neutral after 24 hrs.