Step
| Action
| Yes
| No
|
1
| Were you sent here from the A/C
System Performance Test?
| Go to
Step 2
| Go to
Air Conditioning (A/C) System Performance Test
|
2
|
Caution: Refer to Moving Parts and Hot Surfaces Caution in the Preface section. Feel the liquid
line before the expansion device.
Is the liquid line cold before the expansion device?
| Go to
Step 3
| Go to
Step 8
|
3
| Feel along the surfaces of the following high side components:
• | The compressor discharge hose |
• | The liquid line between the condenser and the expansion device |
Did you detect an abrupt drop in temperature along the surfaces of any
of the listed components?
| Go to
Step 7
| Go to
Step 4
|
4
|
- Feel the liquid line at the expansion device location for extreme
cold, possibly accompanied by heavy frost.
- Feel along the liquid line beyond the expansion device location
for warm temperature.
Is the liquid line extremely cold at the expansion device location and
warm beyond the expansion device location?
| Go to
Step 11
| Go to
Step 5
|
5
| Feel along the surfaces of the following low side components.
• | The evaporator inlet tube between the expansion device and the
evaporator core |
• | The evaporator outlet tube between the evaporator core and the
compressor. |
• | The compressor suction hose |
Did you feel an abrupt temperature change along the surfaces of any
of the listed components?
| Go to
Step 7
| Go to
Step 6
|
6
| Feel along the surfaces of the low and the high side components.
• | The evaporator inlet tube between the expansion device and the
evaporator core |
• | The evaporator outlet tube between the evaporator core and the
accumulator |
• | The compressor suction hose |
• | The compressor discharge hose |
• | The evaporator inlet tube between the condenser and the expansion
device |
Are the temperatures of these components only mildly warm?
| Go to
Step 14
| Go to
Step 8
|
7
|
- Recover the refrigerant. Refer to
Refrigerant Recovery and Recharging
.
- Remove the restriction from the component, or replace the component
which produced an abrupt temperature drop.
Is the repair complete?
| Go to
Step 9
| --
|
8
|
- Recover the refrigerant and evacuate the system. Refer to
Refrigerant Recovery and Recharging
.
- Record the weight of the recovered refrigerant.
- Compare the weight of the recovered refrigerant with the system
capacity. Refer to
Refrigerant System Capacities
.
Is the weight of the recovered refrigerant charge greater than 75% of
the total system capacity?
| Go to
Step 9
| Go to
Step 10
|
9
| Recharge the A/C system. Refer to
Refrigerant Recovery and Recharging
.
Is the cooling performance improved?
| Go to
Step 21
| Go to
Step 10
|
10
|
- Leak test the system. Refer to
Leak Testing
.
- Repair any leaks.
Is the repair complete?
| Go to
Step 21
| --
|
11
| The expansion device is restricted.
Replace the expansion device. Refer to
Expansion (Orifice) Tube Replacement
.
Are metal flakes present?
| Go to
Step 12
| Go to
Step 13
|
12
|
- Remove the compressor hose assembly from the vehicle. Refer to
Compressor Hose Assembly Replacement
.
- Inspect the hose for debris by blowing shop air through one end
of the hose while covering the other end with a shop towel.
- Observe the amount of debris collected in the shop towel.
Did a large amount of debris collect in the shop towel?
| Go to
Step 18
| Go to
Step 20
|
13
| If the expansion device was restricted
with a brown or black residue, perform the following procedure:
- Flush the A/C system. Refer to
Flushing
.
- Replace the accumulator. Refer to
Air Conditioning Accumulator Replacement
.
Are the repairs complete?
| Go to
Step 21
| --
|
14
|
- Recover the refrigerant. Refer to
Refrigerant Recovery and Recharging
.
- Disconnect the compressor hose from the compressor. Refer to
Compressor Hose Assembly Replacement
.
- Inspect for the presence of debris in the compressor suction port.
Is debris present in the compressor suction port?
| Go to
Step 15
| Go to
Step 19
|
15
|
- Remove the debris from the suction port.
- Inspect the expansion device for damage or debris. Refer to
Expansion (Orifice) Tube Replacement
.
Did you find evidence of damage or debris?
| Go to
Step 17
| Go to
Step 16
|
16
| If the expansion device does not show any signs of damage or debris,
perform the following procedure:
- Remove the compressor hose assembly from the vehicle. Refer to
Compressor Hose Assembly Replacement
.
- Inspect the hose for debris by blowing shop air through one end
of the hose while covering the other end with a shop towel.
- Observe the amount of debris collected in the shop towel.
Did a large amount of debris collect in the shop towel?
| Go to
Step 18
| Go to
Step 19
|
17
|
- Replace the expansion device. Refer to
Expansion (Orifice) Tube Replacement
.
- If the expansion device was restricted, observe the type of debris
present.
Are metal flakes present?
| Go to
Step 12
| Go to
Step 13
|
18
| If a large amount of debris was collected in the shop towel from the
compressor hose assembly, perform the following procedure:
- Replace the accumulator. Refer to
Air Conditioning Accumulator Replacement
.
- Install an A/C refrigerant filter. Refer to
Air Conditioning Evaporator Thermal Expansion Valve Screen Replacement
.
Is the repair complete?
| Go to
Step 19
| --
|
19
| Install the compressor hose assembly. Refer to
Compressor Hose Assembly Replacement
.
Are the repairs complete?
| Go to
Step 21
| --
|
20
|
- Install the compressor hose assembly. Refer to
Compressor Hose Assembly Replacement
.
- Install an A/C refrigerant filter. Refer to
Air Conditioning Evaporator Thermal Expansion Valve Screen Replacement
.
- Recharge the A/C system. Refer to
Refrigerant Recovery and Recharging
.
Are the repairs complete?
| Go to
Step 21
| --
|
21
|
- Record the low and the high side pressures and the panel outlet
air temperature after you perform the repairs.
- Compare the pressures and the panel outlet 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 as shown on the A/C Performance
Chart?
| Go to
Step 22
| Go
to
Air Conditioning (A/C) System Performance Test
|
22
| Operate the system in order to verify the repair.
Did you correct the condition?
| System OK
| Go to
Symptoms - HVAC Systems - Manual
in HVAC Systems - Manual
|