Toyota Tacoma manuals

Toyota Corolla Repair Manual: Onvehicle inspection

1. 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:

  1. Normally functioning refrigeration system.

    Gauge reading:
    low pressure side:
    0.15 0.25 Mpa (1.5 2.5 Kgf/cm2) high pressure side:
    1.37 1.57 Mpa (14 16 kgf/cm2)

  1. Moisture present in refrigeration system.

Symptom

Probable cause

Diagnosis

Remedy

During operation, pressure on low pressure side sometimes become a vacuum and sometime normal Moisture in refrigerating system freezes at expansion valve orifice causing a temporary stop of cycle, however, when it melts, normal state is restored.
  • Drier in oversaturected state
  • moisture in refrigerating system freezes at expansion valve orifice and blocks circulation of refrigerant
  1. Replace condenser
  2.  remove moisture in cycle by repeatedly evacuating air
  3.  supply proper amount of new refrigerant
  1. Insufficient cooling

Symptom

Probable cause

Diagnosis

Corrective actions

  • Pressure low on both low and high pressure sides
  • insufficient cooling performance
Gas leakage in refrigeration system
  • Insufficient refrigerant
  • refrigerant leaking
  1. Check for gas leakage and repair if necessary
  2.  supply proper amount of new refrigerant
  3.  if indicated pressure value is close to a 0 when connected to gauge, create the vacuum after inspecting and repairing location of leak
  1. Poor circulation of refrigerant

Symptom

Probable cause

Diagnosis

Corrective actions

  • Pressure low on both low and high pressure sides
  • frost on pipe from condenser to unit
Refrigerant flow obstructed by dirt in receiver Receiver clogged Replace condenser
  1. Refrigerant does not circulate

Symptom

Probable cause

Diagnosis

Corrective actions

  • Vacuum indicated on low pressure side, very low pressure indicated on high pressure side
  • frost or dew seen on piping before and after receiver/ drier or expansion valve
  • Refrigerant flow obstructed by moisture or dirt in refrigerating system
  • refrigerant flow obstructed by gas leaked from expansion valve
Refrigerant does not circulate
  1. Check expansion valve
  2.  clean out dirt in expansion valve by air blowing
  3.  replace condenser
  4.  evaporate air and supply proper amount of new refrigerant.
  5.  For gas leakage from expansion valve, replace expansion valve
  1. Refrigerant overcharged or insufficient cooling of condenser

Symptom

Probable cause

Diagnosis

Corrective actions

  • Pressure too high on both low and high pressure sides
  • Unable to develop sufficient performance due to excessive use of refrigerating system
  • insufficient cooling of condenser
  • Excessive refrigerant in cycle"too much refrigerant supplied
  • condenser cooling insufficient"condenser fins clogged at cooling fan
  1. Clean condenser
  2.  check cooling fan with cooling fan motor operation
  3.  if (1) and (2) are in normal state, check amount of refrigerant and supply proper amount of refrigerant
  1. Air present in refrigeration system

Symptom

Probable cause

Diagnosis

Corrective actions

  • Pressure too high on both low and high pressure sides
  • the low pressure piping too hot to the touch
Air entered in refrigerating system
  • Air present in refrigerating system
  • insufficient vacuum purging
  1. Check compressor oil to see if it is see if it is dirty or insufficient
  2.  evacuate air and supply new refrigerant
  1. Expansion valve improperly

Symptom

Probable cause

Diagnosis

Corrective actions

  • Pressure too high on both low and high pressure sides
  • frost or large amount of dew on piping on low pressure side
Trouble in expansion valve
  • Excessive refrigerant in low pressure piping
  • expansion valve opened too wide
Check expansion valve
  1. Defective compression compressor

Symptom

Probable cause

Diagnosis

Corrective actions

  • Pressure too high on low high pressure sides
  • pressure too low to on high pressure side
Internal leak in compressor
  • Compression failure
  • leakage from valve damaged or broken sliding parts
Repair or replace compressor

Gauge readings (reference)

Replacement

Refrigerant
...

Replacement
1. Discharge refrigerant from refrigeration system  turn the a/c switch on.  operating the cooler compressor at the engine rpm of approx. 1000 For 5 to 6 min., Circulate the refrige ...

Other materials:

Canceling and resuming the constant speed control
1 Pulling the lever toward you cancels the constant speed control. The speed setting is also canceled when the brakes are applied or the clutch pedal (manual transmission) is depressed. 2 Pushing the lever up resumes the constant speed control. Resuming is available when the vehicle speed is mo ...

Onvehicle inspection
1. Inspection throttle body idle speed control valve assy Notice: it is impossible to check the resister value and the operation of isc valve by itself, because the isc valve has an ic circuit inside it, which transforms the duty signal from the ecm to the derive signal. After check ...

Moon roof
Use the overhead switches to open and close the moon roof and tilt it up and down. ■ Opening and closing 1 Opens the moon roof* The moon roof stops slightly before the fully open position to reduce wind noise. Press the switch again to fully open the moon roof. 2 Closes the moon roof* ...

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