90S Quattro (Canada) V6-2.8L (AAH) (1993)
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outside (ambient) temperature must be between 59°F - 113°F (15°C - 45°C)
CHECKING
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switch ignition OFF
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connect high pressure hose of refrigerant recovery/recycling/recharging unit Kent-Moore ACR4, or equivalent, to high pressure service valve
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leave low pressure hose of refrigerant recovery/recycling/recharging unit disconnected
Note
Only a high pressure service valve is used for A/C system servicing and checking pressures. A low pressure service valve is not installed in the A/C
system. Perform all A/C system pressure checks through the high pressure service valve.
IF A/C REFRIGERANT SYSTEM BASE PRESSURE IS LESS THAN SPECIFIED ON CHART, SYSTEM IS LOW ON REFRIGERANT.
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check system for leaks using halogen leak detector Hitec HI400A-TEL or equivalent, repair system as necessary
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check pressure relief valve on A/C compressor.
IF THE PRESSURE RELIEF VALVE HAS BLOWN,
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check triggering of coolant fan according to wiring diagram
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check for pinched, kinked or damaged refrigerant lines/hoses
IF NO PROBLEMS ARE FOUND,
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discharge A/C system, then evacuate and recharge
IF A/C REFRIGERANT SYSTEM PRESSURE CORRESPONDS TO OR IS HIGHER THAN BASE PRESSURE SPECIFIED ON CHART,
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start engine
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adjust A/C to maximum cooling
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A/C compressor clutch engages and compressor is driven
Note
If A/C clutch is not engaged, check voltage supply to A/C clutch according to wiring diagram. If voltage is OK, repair (replace) A/C clutch.
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raise Engine Speed (RPM) to 2000
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note pressure on A/C high pressure gauge Specified high pressure value