Step | Action | Yes | No | ||||||||||||||
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DEFINITION: The low side pressure is lower than normal and the high side pressure is higher than normal. A restriction in the A/C system | |||||||||||||||||
1 | Were you sent here from the A/C System Performance Test? | Go to Step 2 | |||||||||||||||
2 |
Caution: Avoid contact with moving parts and hot surfaces while working around a running engine in order to prevent physical injury. Feel the liquid line before the expansion (orifice) tube. Is the liquid line cold before the orifice? | Go to Step 3 | Go to Step 8 | ||||||||||||||
3 | Feel along the surfaces of the following high side components for a sudden drop in temperature. The high side components should feel warm/hot from the compressor all the way to the orifice.
Is there an abrupt drop in temperature noted along the surfaces of any of the components listed? | Go to Step 7 | Go to Step 4 | ||||||||||||||
4 | Feel the liquid line at the orifice location for extreme cold, possibly accompanied by heavy frost, then feel along the liquid line after the orifice location for warm temperature. Is the liquid line extremely cold at the orifice location and warm after the orifice location? | Go to Step 11 | Go to Step 5 | ||||||||||||||
5 | Feel along the surfaces of the following low side components for a sudden change in temperature:
Is there an abrupt temperature change felt along the surfaces of any of the components listed? | Go to Step 7 | Go to Step 6 | ||||||||||||||
6 | Feel along the surfaces of the following low and high side components to compare the overall temperatures of the low and high sides:
Are the overall temperatures of the low and high side components both only mildly warm? | Go to Step 12 | Go to Step 8 | ||||||||||||||
7 |
Is the repair complete? | Go to Step 18 | -- | ||||||||||||||
8 |
Is the weight of the removed refrigerant charge greater than 75% of the total system capacity? | Go to Step 9 | Go to Step 9 | ||||||||||||||
9 | Recharge the A/C system. Refer to Refrigerant Recovery and Recharging . Is the cooling performance improved? | Go to Step 18 | Go to Step 10 | ||||||||||||||
10 |
Is the repair complete? | Go to Step 18 | -- | ||||||||||||||
11 | Replace the orifice tube. Refer to Expansion (Orifice) Tube Replacement . Is the repair complete? | Go to Step 18 | -- | ||||||||||||||
12 |
Is there debris present on the compressor suction port screen? | Go to Step 13 | Go to Step 17 | ||||||||||||||
13 |
Is there evidence of damage or debris? | Go to Step 15 | Go to Step 14 | ||||||||||||||
14 | If the orifice does not show any signs of damage or debris:
Is there a large amount of debris collected in the shop towel? | Go to Step 16 | Go to Step 17 | ||||||||||||||
15 |
Is the repair complete? | Go to Step 17 | -- | ||||||||||||||
16 | If there was a large amount of debris collected in the shop towel from the compressor hose assembly, replace the accumulator. Refer to Air Conditioning Accumulator Replacement . Is the repair complete? | Go to Step 17 | -- | ||||||||||||||
17 |
Are the repairs complete? | Go to Step 18 | -- | ||||||||||||||
18 |
Are the readings within the specified ranges? | Go to Step 19 | |||||||||||||||
19 | Operate the system in order to verify the repair. Did you find and correct the condition? | System OK |