Pressures and Temperatures

A/C refrigerant system with expansion valve and receiver drier







Pressures and temperatures in the A/C system vary depending on engine speed (RPM), cool and fan speed, engine coolant temperature, A/C clutch engagement, outside temperature and humidity, cooling demand etc.

Pressure and temperature specifications are to be used as a reference only, and are based on the following operating conditions:
- Engine speed 1500 - 2000 RPM
- Outside temperature of 20 °C (68 °F)

Component listing, pressure and temperature specifications Pressure, Vacuum and Temperature Specifications

To check system pressures, pressure testing equipment must be connected to the service valves. Checking refrigerant system pressures. Refer to A/C "Refrigerant System, Testing With Pressure Gauges" Testing and Inspection


NOTE:
- Small - arrows - indicate direction of refrigerant flow.
- At 20 °C (68 °F) with engine not running, refrigerant system pressure equalizes to approx. 4.7 bar (68.2 psi).
- Refrigerant system pressures are regulated and maintained within certain tolerances by the variable displacement compressor independent of engine speed (RPM).
ND = low pressure side
HD = high pressure side