Hummer H1 Service Manual page 730

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®
Condition
Low Side High
High Side High
(Discharge Air Warm -
Discharge Line Warm to
Hot)
Low Side High
High Side High
(Discharge Air Slightly
Cool - Discharge Line
Cool)
Low Side Low
High Side Low
Low Side High
High Side Low
Low Side Low
High Side High
Low Side and High Side
Normal But Cooling is
Inadequate
05745159
Heating/Ventilation/Air Conditioning (HVAC)
A/C Pressure Test Diagnosis
Possible Cause
1. Condenser fins obstructed or distorted.
2. System overcharged.
3. Air in system.
4. Expansion valve failed.
5. Condenser restricted.
6. Compressor drive belt slipping.
1. Air and moisture in system.
2. Leak at A/C line of 1/2 ounce or less.
1. System low on refrigerant.
2. Expansion valve failed.
1. Internal leak in compressor
2. Expansion valve failure.
3. Drivebelt slip.
1. Expansion valve failed.
2. A/C hose constricted, plugged.
3. Receiver/Dryer restricted or has failed.
4. Condenser problem (blocked, damaged).
1. Air and/or moisture in system.
2. Receiver/Dryer fault.
Correction
1. Clear obstruction with water spray and
compressed air. Straighten distorted fins
with tool J–36847 or equivalent.
2. Recover excess charge with A/C service
cart J–39500-A.
3. Evacuate and recharge system.
4. Replace valve.
5. Replace condenser. Evacuate and recharge
system.
6. Replace belt or belt tensioner as needed.
1. Discharge system. Replace receiver/dryer
and evacuate - recharge system.
2. Locate with D-Tek leak tester. Recharge
system and verify proper operation.
1. Add refrigerant and leak test system. Cor-
rect leak source and recharge as needed.
NOTE: If leak was large, check compres-
sor oil level also and correct as needed.
2. Replace valve, then evacuate and recharge
system.
1. Replace compressor and evacuate -
recharge system.
2. Discharge system. Replace valve and
recharge system.
3. Replace belt.
1. Discharge system. Replace valve and
recharge.
2. Check hose for kinks. Replace hose if
plugged and evacuate - recharge system.
3. Evacuate system. Replace receiver/dryer
and recharge system.
4. Evacuate system. Replace condenser and
recharge system.
1. Leak test system. Repair leaks if neces-
sary. If leaks are not evident, evacuate and
recharge system.
2. Evacuate system, replace receiver/dryer
and recharge system.
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