Checking For Leaks

CHECKING FOR LEAKS

Manifold Gauge Set:

1. Attach the manifold gauge set. Leave both manifold gauge valves at the maximum clockwise (closed) position. Both gauges should show approximately 60 to 80 pounds pressure at 24°C (75°F) with the engine not running.
2. If very little or no pressure is indicated, leave the vacuum pump valve closed, open the Refrigerant-12 tank valve, and set the low pressure (suction) manifold gauge valve to the counterclockwise position. This opens the system to tank pressure.
3. Check all refrigerant line connections, and the compressor for leaks, using a good refrigerant leak detector.

NOTE: If the surrounding air is contaminated with refrigerant gas, the leak detector will indicate this gas all the time. Good ventilation is necessary to prevent this situation. A fan, even in a well ventilated area, is very helpful in removing small traces of refrigerant vapor.

Flame-Type Leak Detector:

a. One type of leak detector is a flame-type detector Rotunda model 23-006 or equivalent.

WARNING: With a flame-type detector Rotunda model 23-006 or equivalent, avoid inhaling the fumes from the leak detector.

NOTE: The smaller the flame the more sensitive it is to leaks. Therefore, to ensure accurate leak indication keep flame as small as possible. The copper element must be red hot. If it is burned away, replace the element. Hold the open end of the hose just below each suspected leak point for two or three seconds. The flame will normally be almost colorless. The slightest leak will be indicated by a bright green blue color to the flame. Be sure to check the manifold gauge set and hoses for leaks as well as the rest of the system.

Electronic Leak Detector:

b. Another testing device can be used to detect leaking refrigerant gas. This device is called the Electronic Leak Detector Rotunda model 55-0007 or equivalent. The control switch of the electronic leak detector has three positions, OFF, calibrate (CAL) and operate (OPR). It also has a sensitivity control knob and a flexible sensing probe.

NOTE: The electronic leak detector is operated by turning the control switch to the CAL position and adjusting the sensitivity (SENS) control knob until a slow steady ticking sound is audible. The control switch is then placed in the operate (OPR) position. Then move the probe at about 25 mm (1 inch) per second in the suspected area. When escaping refrigerant gas is located, the ticking signal will increase in ticks per second. If the gas is relatively concentrated the signal will be increasingly shrill. Follow the instructions included with the detector to improve handling and operating techniques.