LaCrosse 90 bottle machine

[Alan]

I have a LaCrosse 90 Pepsi machine. I recently had to replace the condenser fan and had it checked for freon. It was very low and takes r 12 that is not available. I had the r 12 vacuumed out and replaced it with Red Tek R12a. I then watched it cycle through several times. It is half full of bottled water. The thermostat setting is on 1.5. It does cool and the fans are running. The compressor is shutting off at 35.5 degrees and turning back on at 45 degrees. The temp of the water is 37 degrees. It runs for 45 minutes and then cycles off for 35 minutes. The door gaskets are good and not leaking. Compressor sounds normal. One copper line is showing frost from the bottom of the cooler going down about eight inches and there is no frost on the evaporator coil. Is it normal to run this long?