Compressor Isolation Method: Isolating

Remove caps from compressor service valve stems and service ports. Connect manifold gauge set to service port connection, purge test hoses, then crack compressor service valves so that system pressures are indicated on test gauges.
If system has been fully discharged previously (zero high pressure gauge reading), system should be slightly charged so that high pressure gauge reading is above zero to prevent air arid moisture entering when connections are broken.
Front-seat suction (inlet) service valve by turning valve stem in fully. Operate the compressor until low side (suction) gauge reading drops to 2 psi. Stop compressor, front-seat discharge (outlet) service valve by turning valve in fully and disconnect the compressor clutch lead to prevent compressor operation with this valve front-seated.
CAUTION: Compressor must never be operated with this discharge valve front-seated (closed) at damage to compressor valves would result. Compressor is now isolated from system.