Refrigerant System Performance

Refrigerant Pressure & Temperature Charts:

1. Connect manifold gauge set to system.
2. Start engine and turn on A/C system.
3. As soon as system is stabilized, record high and low pressures as shown by manifold gauges.
4. High side pressure should read 178-235 psi. As low pressure drops, high pressure should rise.
5. When clutch disengages, low side pressure should rise and high side pressure should drop.
6. Determine A/C clutch cycle rate per minute (1 cycle is A/C clutch ON time plus OFF time).
7. Record A/C OFF time in seconds.
8. Record A/C ON time in seconds.
9. Record center duct temperature.
10. Determine and record ambient temperature.
11. Compare test readings with chart.