Symptoms - HVAC Systems - Manual. Chevrolet Joy 2008

For 1990-2009 cars

Table 1: | Discharge High Pressure Abnormally High
Table 2: | Discharge Pressure Abnormally Low
Table 3: | Suction Low Pressure Abnormally Low
Table 4: | Suction Pressure Abnormally High
Table 5: | Suction and Discharge Pressure Abnormally High
Table 6: | Suction and Discharge Pressure Abnormally Low
Table 7: | Refrigerant Leaks

#### Discharge High Pressure Abnormally High

Symptoms | Checks | Actions
--- | --- | ---
After stopping the compressor, the pressure drops quickly, then fails gradually. | There is air in the system. | Recover, evacuate, and recharge the system with the specified amount of refrigerant.
The condenser is excessively hot. | There is excessive refrigerant in the system. | Recover, evacuate, and recharge the system with the specified amount of refrigerant.
Reduced or no air flow through the condenser | The condenser or the radiator fins are clogged. | Clean the condenser or the radiator fins.

The condenser or the radiator fan is not working properly.

• | Check the voltage and the fan RPM.

• | Check the fan direction.

The line to the condenser is excessively hot. | Restricted flow of refrigerant in the system | Locate and repair the restriction.

#### Discharge Pressure Abnormally Low

Symptoms | Checks | Actions
--- | --- | ---

The condenser is not hot.

Insufficient refrigerant in the system

• | Check the system for a leak.

• | Charge the system.

High and low pressures are balanced soon after stopping the compressor. Low side pressure is higher than normal. | Faulty compressor | Repair or replace the compressor.
The outlet of the expansion valve is not frosted, low pressure gage indicates vacuum. | Faulty expansion valve | Replace the expansion valve.
Moisture in the system | Recover, evacuate, and recharge the system.

#### Suction Low Pressure Abnormally Low

Symptoms | Checks | Actions
--- | --- | ---
The condenser is not hot. | Insufficient refrigerant in the system | Repair the leaks. Recover, evacuate, and recharge the system.
The expansion valve is not frosted and the low pressure line is not cold. Low pressure gage indicates a vacuum. | Frozen/Faulty expansion valve | Replace the expansion valve.
Discharge temperature is low and the air flow from the vents is restricted. | The evaporator is frozen. | Clear the restricted evaporator case drain.
The expansion valve is frosted. | The expansion valve is clogged. | Clean or replace the expansion valve.
The receiver/dryer outlet is cool and the inlet is warm. | The receiver/dryer is clogged. | Replace the receiver/dryer.

#### Suction Pressure Abnormally High

Symptoms | Checks | Actions
--- | --- | ---
Low pressure hose and check joint are cooler than the temperature around the evaporator. | The expansion valve is opened for too long. | Replace the expansion valve.
Suction pressure is lowered when the condenser is cooled by water. | There is excessive refrigerant in the system. | Recover, evacuate, and recharge the system.

#### Suction and Discharge Pressure Abnormally High

Symptoms | Checks | Actions
--- | --- | ---
Reduced airflow through the condenser | The condenser or the radiator fins are clogged. | Clean the condenser and the radiator.

The radiator cooling fans are not working properly.

• | Check the condenser and the radiator.

• | Check the fan direction.

The condenser is excessively hot. | There is excessive refrigerant in the system. | Recover, evacuate, and recharge the system.

#### Suction and Discharge Pressure Abnormally Low

Symptoms | Checks | Actions
--- | --- | ---
Low pressure hose and metal end areas are cooler than the evaporator. | Clogged or kinked low pressure hose | Repair or replace the low pressure hose.
Temperature around the expansion valve is low compared to that around the receiver/drier. | The high pressure line is clogged. | Repair or replace the high pressure line.

#### Refrigerant Leaks

Symptoms | Checks | Actions
--- | --- | ---
The compressor clutch is dirty. | The compressor shaft seal is leaking. | Repair or replace the compressor.
The compressor bolts are dirty. | Leaking around a compressor housing bolt | Tighten the bolts or replace the compressor.

The compressor gasket is wet with oil.

• | The compressor gasket is leaking.

• | Poor tightening in the system

• | The O-ring is faulty.

• | Repair or replace the compressor.

• | Retighten the connection--coupling, bolt, etc.

• | Replace the O-ring.