DEFINITION: The low side pressure is higher than normal and the high side pressure is lower than normal.

Were you sent here from the A/C system Performance Test?

Go to Step 2

Go to Air Conditioning (A/C) System Performance Test

After continued operation of the A/C system, do the low and high side pressures equalize or become static?

Go to Step 5

Go to Step 3

Refer to the pressures recorded during the A/C system Performance Test.

Inspect for the following conditions:

Caution: Refer to Moving Parts and Hot Surfaces Caution in the Preface section.

Do the listed conditions exist?

Go to Step 5

Go to Step 4

Refer to the pressures recorded during the A/C system Performance Test.

Inspect for the following conditions:

Caution: Refer to Moving Parts and Hot Surfaces Caution in the Preface section.

Do the listed conditions exist?

Go to Step 5

Go to Air Conditioning (A/C) System Performance Test

The A/C system has a low A/C refrigerant charge.

Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging .

Is the procedure complete?

Go to Step 6

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1. After you perform the repairs, record the following:

•	The low and the high side pressures

•	I/P panel outlet air temperature

2. Compare the pressures and the temperature to those listed in the A/C Performance Chart. Refer to Air Conditioning (A/C) System Performance Test .

Are the readings within the specified ranges?

Go to Step 13

Go to Step 7

The A/C compressor is malfunctioning.

Remove the expansion device and inspect for contamination. Refer to Expansion (Orifice) Tube Replacement .

Are there metal flakes on the expansion device?

Go to Step 9

Go to Step 8

Inspect the expansion device for a brown, powdery residue indicating desiccant in the A/C system.

Is there a brown, powdery residue present?

Go to Step 11

Go to Step 12

1. Remove the A/C compressor hose from the A/C compressor. Refer to Compressor Hose Assembly Replacement .
2. Inspect for metal flake contamination at the line connections and the A/C compressor ports.

Is there metal flake contamination present?

Go to Step 10

Go to Step 12

1. Replace the A/C compressor. Refer to Air Conditioning Compressor Replacement .
2. Install an A/C refrigerant filter. Refer to Air Conditioning Evaporator Thermal Expansion Valve Screen Replacement .
3. Replace the orifice tube. Refer to Expansion (Orifice) Tube Replacement .
4. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging .

Is the repair complete?

Go to Step 13

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1. Flush the A/C system. Refer to Flushing .
2. Replace the orifice tube. Refer to Expansion (Orifice) Tube Replacement .
3. Replace the A/C compressor. Refer to Air Conditioning Compressor Replacement .
4. Replace the accumulator. Refer to Air Conditioning Accumulator Replacement .
5. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging .

Is the repair complete?

Go to Step 13

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1. Replace the A/C compressor. Refer to Air Conditioning Compressor Replacement .
2. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging .

Is the repair complete?

Go to Step 13

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Operate the A/C system in order to verify the repair

Did you find and correct the condition?

System OK

Go to Symptoms - HVAC Systems - Manual in HVAC Systems-Manual

or

Symptoms - HVAC Systems - Automatic in HVAC Systems-Automatic