System Performance Test

System Performance Test Figure 2:

Pressure-Temperature Relationship Of R-134a Figure 3:

PERFORMANCE TEST

Tool Required:

- J 21213-A Four Jack-Dual Range Temperature Tester or Equivalent

Prior to the performance test, a functional test should be performed. Refer to Functional Test.
Functional Test/Check

1. Park vehicle inside or in a shaded area.

2. Open doors or windows to ventilate interior.

3. Vent engine exhaust, if necessary.

4. Open the hood and install high and low side pressure gages. Route the lines over the rear hood seal, and tape the gages to the windshield for viewing.

5. Close the hood to the safety latch position.

6. Record the ambient temperature at the vehicle.

7. Record relative humidity. Use psychrometer or consult local weather bureau.


IMPORTANT: Be sure to record relative humidity and ambient temperature conditions at time of test.

8. Close doors or windows.

9. Set mode control to MAX A/C, adjust blower speed to HI, and temperature to full Cold.

10. Open air conditioning outlets.

11. Install J 21213-A or equivalent into right center air conditioning outlet.

12. Place transmission in PARK or NEUTRAL.

13. Start engine, stabilize engine speed at 1500 RPM, and start the timer.

14. Run the air conditioning system until outlet air reaches the lowest temperature (about 3 minutes).

15. Record outlet air temperature and high-side and low-side pressures.

16. Turn the engine off and compare the readings. Normally operating air conditioning systems should not exceed the levels shown in figures.


Inspect

If a malfunction in the refrigerant system is suspected due to abnormal system pressures, inspect the following:

1. Outer surfaces of radiator and condenser cores. Make sure air flow is not blocked by dirt, leaves or other foreign material. Be sure to check between the condenser and radiator as well as the outer surfaces.

2. Evaporator core, condenser core, hoses, tubes, etc. for restrictions and kinks.

3. Refrigerant leaks.

4. All air ducts for leaks or restrictions. Low air flow rate may indicate a restricted evaporator core.

5. Compressor clutch for slippage.

6. Drive belt for improper tension. If the problem is not found, continue with diagnostic procedures, refer to A/C Performance Charts.
Testing and Inspection