Checking Refrigerant Leaks

INSPECTION FOR REFRIGERANT LEAKS
To facilitate inspection for refrigerant leaks, establish the following conditions:

^ Start engine.
^ Run air conditioner.
^ Set blower fan control to MAX.
^ Set temperature control to FULL COLD.
^ Run the refrigerant system for more than 5 minutes after setting the above-mentioned conditions (to circulate refrigerant through the system).

Refrigerant Leak Chart:

Refrigerant leaks should be checked immediately after stopping engine, beginning with high pressure line, using a gas leak detector. This is because the pressure in high pressure line drops gradually after refrigerant circulation stops while the pressure in low pressure line rises gradually as shown in the graph at left. Leaks can be detected easily when pressure is high.

To prevent detecting errors, make sure that there is no refrigerant vapor or tobacco smoke in the vehicle vicinity. It is also necessary to shield vehicle from wind so that leaking refrigerant is not blown away.

Refrigerant Lines:

INSPECTION POINTS
Check carefully each tube joint. To check, wipe the portion to be checked with waste cloth, and move tester probe all around the joint.

Compressor
Check shaft seals and bolt holes, and also around magnet clutch.

Receiver drier
Check pressure valve, safety valve and fusible plug mounts.

Service valve
Check all around service valves.
Ensure that valve core is not loose.
Service valve caps, must be attached to valves (to prevent leak).
Also check that there are no foreign objects inside caps.

Inside of cooling unit
To check, insert leak tester probe into drain hose immediately after stopping engine. (Keep probe inserted for more than 10 seconds.)