Refrigerant: Testing and Inspection

ON-VEHICLE INSPECTION







1. INSPECT REFRIGERANT VOLUME
a. Observe the sight glass on the liquid tube.

Test conditions:
- Running engine at 1500 rpm

- Single A/C:
Front blower speed control dial at "HI" position

- Dual A/C:
Front and rear blower speed set at "HI" position

- A/C switch ON
- Single A/C:
Front temperature control dial at "MAX. COOL" position

- Dual A/C
Front temperature control dial at "MAX. COOL" position

Rear temperature control set at 18.5 degrees C (65 degrees F)

- Fully open the doors

2. INSPECT REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET
a. This is a method for checking the A/C system by using a manifold gauge set. Read the manifold gauge pressure when the conditions below are met. Test conditions:
- Temperature at the air inlet with R/F switch set at RECIRC is 30 to 35 degrees C (86 to 95 degrees F)
- Engine running at 1500 rpm
- All doors are fully open
- Blower speed control switch is at "HI" position
- Temperature control dial at "MAX. COOL" position
- Dual A/C:
Rear temperature control set at 18.5 degrees C (65 degrees F)

HINT: Gauge indications may vary slightly due to ambient temperature conditions.

1. Normally functioning refrigeration system.










Gauge reading:







2. Moisture present in refrigeration system.




3. Insufficient cooling




4. Poor circulation of refrigerant




5. Refrigerant does not circulate




6. Refrigerant overcharged or insufficient cooling of condenser




7. Air present in refrigeration system






NOTE: These indications are shown when the refrigeration system has been opened and the refrigerant has been charged without vacuum purging.




8. Expansion valve malfunction




9. Insufficient compressor compression

3. INSPECT IDLE-UP SPEED
a. Warm up the engine.




b. Inspect idle-up speed when the following conditions are established.
- Warm up engine
- Blower speed control switch at "HI" position
- A/C switch ON " Temperature control dial at "COOL" position

If idle speed is not as specified, check the Idle control system.

4. INSPECT FOR LEAKAGE OF REFRIGERANT
a. perform under the following conditions:
- Stop the engine.
- Secure good ventilation (If not, the gas leak detector may react to volatile gases witch are not refrigerant, such as evaporated gasoline and exhaust gas.)
- Repeat the test 2 or 3 times.
- Make sure that there is some refrigerant remaining in the refrigeration system. When the compressor is OFF: approx. 392 to 588 kPa (4 to 6 kgf/sq.cm, 57 to 85 psi)

b. Bring the gas leak detector close to the drain hose before performing the test.

HINT:
- After the blower motor stopped, leave the cooling unit for more than 15 minutes.
- Bring the gas leak detector sensor under the drain hose.
- When bringing the gas leak detector close to the drain hose, make sure that the gas leak detector does not react to the volatile gases.
If such reaction is unavoidable, the vehicle must be lifted up.

c. If gas leak is not detected on the drain hose, remove the blower motor linear controller from the cooling unit. Then insert the gas leak detector sensor into the unit and perform the test.
d. Disconnect the connector and leave the pressure switch for approx. 20 minutes. Then bring the gas leak detector close to the pressure switch and perform the test.
e. Bring the gas leak detector close to the refrigerant lines and perform the test.