An AC system operates normally for about 10 miles of driving and then stops cooling.
Moisture contamination in the refrigeration system.
A system that stops cooling after a period of operation could be caused by several problems.
A defective capillary tube would not be affected solely by period of operation. If it were defective it would affect cooling at all times. A refrigerant overcharge and condenser restriction is going to affect system operation from the beginning of the systemís operation. Moisture in the refrigerant in the refrigeration system would create an ice blockage at the orifice tube or TXV.
After the system is shut down the ice would melt, allowing the system to resume normal operation until the ice blockage occurs again. The desiccant in the receiver/drier or accumulator is intended to absorb and hold moisture to prevent this problem. Saturation of the desiccant allows moisture to circulate with the refrigerant.