As we discuss in this brief, the administrationâs reports to the court do not preclude the Legislature from assessing the measures identified by the administration and considering its own strategy for compliance with the court ruling based on its priorities.
The two most common causes of low head pressure at an air conditioner or heat pump compressor motor are: 1  Refrigerant under-charge, due to a refrigerant leak or improper charge.  TXV (TEV) malfunction, over-metering refrigerant.
Purpose of the Pressure Cap. When the pressure inside the cooling system increases above its psi rating, the pressure cap releases some of the coolant into the overflow tank. It does this by use of a spring loaded valve. Once enough coolant has exited the system to reduce the pressure, the valve closes again.