Discharging System

Fig. 2 Manifold gauge set hose connections (Typical):

1. Connect gauges into system, Fig. 2, and adjust controls for maximum cooling. This is necessary when the system has not been operating to return excess oil to the compressor.
2. Operate engine for 10 to 15 minutes to stabilize the system at 1500---1750 rpm.
3. Adjust engine speed to slow idle, then shut "OFF" engine and controls.
4. Open low side hand manifold valve slightly, using a container to catch oil and refrigerant. Do not discharge the refrigerant near an open flame as a toxic gas (phosgene) can result.
5. Allow all refrigerant to discharge through the low side fitting only. Open hand valve(s) only enough to bleed refrigerant from system. Too rapid purging will draw excessive oil from compressor and system.
6. When refrigerant ceases to bleed from the discharge hose on the low side, crack open the high side hand valve to check for any remaining pressure. If pressure does exist, allow high side to discharge slowly. This condition indicates a high side restriction, and it must be diagnosed and corrected before evacuating and charging the system.