Figure 3-6. R22 Refrigerant System Servicing (Sheet 4 of 10)
Do not evacuate the refrigerant system if system has not been completely recovered.
If not already accomplished, attach manifold gage sets (1) per para 3.9.1.a. and recover the
Set manifold gage valves (3) and (4) to their open (back seated) position.
Turn manifold gage valves (3) and (4) clockwise to mid-position.
Connect vacuum pump to center hose (13).
Turn vacuum pump on and open manifold gage valves (3) and (4).
High side gage should drop to 0 (zero) or below. If not, a blockage in air conditioning is
indicated. Locate and clean blockage.
28 to 30 inches of vacuum should be sustained on the low pressure gage for at least ten
minutes. If not, a leak in the air conditioning system is indicated. Locate source of leak and
repair as necessary.
(6) Evacuate system for 45 minutes while monitoring low pressure gages for 28-30 inches vacuum.
Turn manifold gage valves (3) and (4) on manifold gage sets (1) clockwise to their closed (front
Turn off vacuum pump and disconnect from center hose (13).