When the Machine goes into harvest I get pressures that correspond to the book (170Head/80-85Suction) however, the ice will come free on the left hand side of the evaporator, and then melt out of the right side until it finally drops(it eventually locks out on long harvest). I used sanitizer but it made no difference. One thing I noticed was the discharge line would start out at 160 plus degrees, and then would be room temperature, but the pressure was still 80 to 85 lbs. I find it hard to be under charged being my pressures are so close, but could this be the case?
On a side note, it is always the right hand side of the evaporator that gets "stuck"