On-Vehicle Inspection: Notes

INSPECT REFRIGERANT VOLUME
1. Observe the sight glass on the liquid tube.
  
  Fig 1: Identifying Sight Glass
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Test conditions:
  - Running engine at 1,500 rpm
  - Blower speed control switch at "HI"
  - A/C switch ON
  - Temperature control dial at "MAX. COOL"
  - Fully open the doors
    
    Fig 2: Refrigerant Symptoms Table
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET
1. This is a method in witch the trouble is located by using a manifold gauge set. Read the manifold gauge pressure when the these conditions are established.
  Test conditions:
  - Temperature at the air inlet with the switch set at RECIRC is 30 - 35°C (86 - 95°F)
  - Engine running at 1500 rpm
  - Blower speed control switch at "HI" position
  - Temperature control dial at "COOL" position
  - A/C switch ON
  - Fully open doors
  1. Normally functioning refrigeration system.
    Gauge reading:
    
    Low pressure side:
    
    0.15 - 0.25 MPa (1.5 - 2.5 kgf/cm ² )
    
    High pressure side:
    
    1.37 - 1.57 MPa (14 - 16 kgf/cm ² )
    
    Fig 3: Identifying Gauge Reading For Normally Functioning Refrigeration System
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. Moisture present in refrigeration system.
    
    Fig 4: Identifying Gauge Reading For Moisture Present In Refrigeration System
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    
    Fig 5: Symptom Cause Table - Moisture Present In Refrigeration System
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. Insufficient cooling
    
    Fig 6: Identifying Gauge Reading For Insufficient Cooling
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    
    Fig 7: Symptom Cause Table - Insufficient Cooling
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. Poor circulation of refrigerant
    
    Fig 8: Identifying Gauge Reading For Poor Circulation Of Refrigerant
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    
    Fig 9: Symptom Cause Table - Poor Circulation Of Refrigerant
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  5. Refrigerant does not circulate
    
    Fig 10: Identifying Gauge Reading For Refrigerant Does Not Circulate
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    
    Fig 11: Symptom Cause Table - Refrigerant Does Not Circulate
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  6. Refrigerant overcharged or insufficient cooling of condenser
    
    Fig 12: Identifying Gauge Reading For Refrigerant Overcharged Or Insufficient Cooling Of Condenser
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    
    Fig 13: Symptom Cause Table - Refrigerant Overcharged Or Insufficient Cooling Of Condenser
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  7. Air present in refrigeration system
    
    Fig 14: Identifying Gauge Reading For Air Present In Refrigeration System
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    
    Fig 15: Symptom Cause Table - Air Present In Refrigeration System
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  8. Expansion valve improperly
    
    Fig 16: Identifying Gauge Reading For Expansion Valve Improperly
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    
    Fig 17: Symptom Cause Table - Expansion Valve Improperly
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  9. Defective compression compressor
    
    Fig 18: Identifying Gauge Reading For Defective Compression Compressor
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    
    Fig 19: Symptom Cause Table - Defective Compression Compressor
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002