Chapter 8 Troubleshooting & Service Procedures
In this illustration we have
noted how refrigerant is
added to the air conditioner.
Before adding refrigerant to the system you should study the sight glass
while the engine is running and the air conditioner is on. Even if you
found a leak during the system inspection and corrected it, you have no
way of knowing how much refrigerant has leaked. You will not be able to
tell how much refrigerant is in there, but you can see if bubbles are
Then check the gauges for unusually high or low readings, or a lack of
pressure. Following this procedure, and using your knowledge and experi-
ence, decide if it is safe and makes sense to add refrigerant in order to
make your full performance inspection.
You are now ready to add refrigerant to the system. For your safety and
to prevent system damage use the following procedure.
1. Turn on the engine and set the idle at 1200 to 1500 RPM and
then turn on the air conditioner.
Do not open the high pressure hand valve on the mani-
fold gauge set. The compressor could pump refrigerant
into the container and cause it to BURST. Be sure to
keep the refrigerant container upright to prevent liquid
refrigerant from entering the compressor.
2. Open the refrigerant dispensing valve on the container and
then the low pressure hand valve on the manifold. This allows
refrigerant to enter the system as a gas on the low pressure or
suction side of the compressor. The compressor will pull re-
frigerant into the system.