Heating, Ventilation and Air Conditioning


A/C System Service
Performance Test
The performance test will help determine if the air con-
ditioning system is operating within specifications.
Only use service equipment that is U.L.-listed and is cer-
tified to meet the requirements of SAE J2210 to remove
HFC-134a (R-134a) from the air conditioning system.
CAUTION: Exposure to air conditioner refrigerant
and lubricant vapor or mist can irritate eyes, nose
and throat. Avoid breathing the air conditioner
refrigerant and lubricant vapor or mist.
If accidental system discharge occurs, ventilate work
area before resuming service.
R-134a service equipment or vehicle air conditioning sys-
tem should not be pressure tested or leak tested with
compressed air.
Some mixtures of air and R-134a have
been shown to be combustible at elevated pressures
and can result in fire or explosion causing injury or
property damage. Never use compressed air to pres-
sure test R-134a service equipment or vehicle air
conditioning systems.
Additional health and safety information may be obtained
from the refrigerant and lubricant manufacturers.
1. Connect a R-134a refrigerant Recovery/Recycl-
ing/Charging System to the car as shown following
the equipment manufacturer’s instructions.
2. Insert a thermometer in the center vent outlet.
Determine the relative humidity and air
temperature by calling the local weather informa-
tion line.
3. Test conditions:
• Avoid direct sunlight.
• Open engine cover.
• Open front doors.
• Set the temperature control dial to MAX COOL
and push the mode control button to VENT and
FRESH button.
• Turn the fan switch to MAX.
• Run the engine at 1,500 RPM.
• No driver or passengers in vehicle.
4. After running the air conditioning for 10 minutes
under the above test conditions, read the delivery
temperature from the thermometer in the dash vent
and the high and low system pressure from the A/C
Recovery/Recycling/Charging System

5. To complete the charts:
• Mark the delivery temperature along the vertical
• Mark the intake temperature (air temperature)
along the bottom line.
• Draw a line straight up from the air temperature
to the humidity.
• Mark a point one line above and one line below
the humidity level. (10% above and 10% below
the humidity level)
• From each point, draw a horizontal line across to
the delivery temperature.
• The delivery temperature should fall between the
two lines.
• Complete the low side pressure test and high side
pressure test in the same way.