AC/Air Conditioning System — Refrigeration System Checking of Refrigerant Volume, page 21

REFRIGERATION SYSTEM
Checking of Refrigerant Volume

1. RUN ENGINE AT APPROX. 2,000 RPM

2. OPERATE AIR CONDITIONER AT MAXIMUM COOLING
FOR A FEW MINUTES

3. CHECK AMOUNT OF REFRIGERANT
Observe the sight glass on the receiver.

Item | Symptom | Amount of refrigerant | Remedy

1 | Bubbles present in sight glass | Insufficient | Check for leak with gas leak detector

2 | No bubbles present in sight glass | Empty, proper or too much | Refer to items 3 and 4

3 | No temperature difference between compressor inlet and outlet | Empty or nearly empty | Evacuate and charge system. Then check for leak with gas leak detector

4 | Temperature between compressor inlet and outlet is noticeably different | Proper or too much | Refer to items 5 and 6

5 | Immediately after the air conditioner is turned off, refrigerant in sight glass stays clear | Too much | Discharge the excess refrigerant to specified amount

6 | When the air conditioner is turned off, refrigerant foams and then stays clear | Proper | —

Installation of Manifold Gauge Set

1. CLOSE BOTH HAND VALVES OF MANIFOLD GAUGE SET

2. INSTALL CHARGING HOSES OF GAUGE SET TO CHARGING VALVES

Connect the low pressure hose (Blue) to the low pressure charging valve and the high pressure hose (Red) to the high pressure charging valve. Tighten the hose nuts by hand.
HINT: Do not apply compressor oil to the seat of the connection.