Identifying Refrigerant Purity
Notice: The purity of the system refrigerant should be confirmed before any other diagnostics
are begun. The RI-2002DS refrigerant identifier has the ability to identify R-12,
R134a, R-22, potentially dangerous hydrocarbons, and non-condensable gases (NCG) such
as air. If the A/C system contains anything less than 98 percent pure refrigerant,
the refrigerant is considered contaminated and the temperature/pressure charts will
not be valid. Contaminated refrigerant should not be recovered as it will contaminate
the recovery machine and refrigerant supply tank. Air is not considered a contaminate
as it can be purged.
- Turn On the refrigerant identifier and let it reach operating temperature,
3-5 minutes.
- When the display reads HOSE, and with the vehicle turned Off, attach the
hose to the low side suction port and open the service valves.
- Press the ENTER button.
- The display will read GAS as a sample of refrigerant is taken and analyzed.
- When analysis is complete, the display will show, by percentage, the make-up
of the gas.
- If the refrigerant is less than 98 percent pure the temperature/pressure
charts will not be accurate for system diagnosis. If the refrigerant is pure but contains
air, the system should be recovered and recharged with virgin refrigerant before proceeding.
Installing Manifold Gage Set
If an A/C system problem still exists after you have completed the preliminary
checks, more diagnostic tests must follow. These include manifold gage set readings.
Follow the steps listed below for installing a manifold gage set.
Caution: Always wear goggles and wrap a clean cloth around fittings, valves, and connections
when performing work that involves opening the refrigerant system.
Caution: Beware of the danger of carbon monoxide fumes by running the engine in closed
or improperly ventilated garages.
Important: Check to make sure gages read zero before installing manifold gage set.
- Close both hand valves of the manifold gage set.
Low side gage (1)
High side gage (2)
- Connect the low pressure blue gage hose to the suction service port located
on the suction pipe. Pull the valve assembly collar up, and place the valve assembly
over the service port and release the collar.
- Open the service valve.
- Connect the high pressure red gage hose to the discharge service port located
on the discharge pipe. Pull the valve assembly collar up, and place the valve assembly
over the service port and release the collar.
- Open the service valve.
Performance Test - Service Stall
Important: If the ambient air temperature is lower than 5°C (40°F), the A/C compressor
will not be enabled.
Important: This test must be performed in a service stall environment that protects the
vehicle from wind that could cause incorrect pressure/temperature readings.
- Start the engine and warm to the operating temperature.
- Install the thermometer in the right center outlet.
- Open the doors and windows to stabilize the interior temperature with
the outside ambient air temperature.
- Depress the recirc button.
- Set the temperature knob to full cold.
- Select the 3rd blower speed.
- Depress the A/C button.
- Run the engine at 2,000 RPM.
- Continue running until teh system pressures and outlet temperature stabilizes.
Usually 5 to 7 minutes.
- Record the A/C system pressures and outlet temperatures every 5 minutes.
- Compare the readings to the normal system performance charts then continue
down the diagnostic flow chart.
Performance Test - 72 km/h (45 mph)
Important: If the ambient air temperature is lower than 5°C (40°F), the A/C compressor
will not be enabled.
- Start engine and warm to operating temperature.
- Install thermometer in right center outlet.
- Recirc Off (Outside Air).
- Set temp to full cold.
- Select 3rd blower speed.
- Depress A/C button.
- Drive vehicle at 72 km/h (45 mph).
- Record A/C system pressure and outlet temperatures every minute for 5 minutes.
- Compare readings to system performance charts and perform additional diagnostics
as required.