E 150 V8-5.4L (2008)
Accumulator HVAC: Description and Operation
SUCTION ACCUMULATOR
NOTE: Installation of a new suction accumulator is not required when repairing the A/C system, except when there is physical evidence of
contamination from a failed A/C compressor or damage to the suction accumulator. Damage to the suction accumulator includes leaks in the suction
accumulator, physical damage to the suction accumulator shell or desiccant, or moisture contamination. Moisture contamination results only from a
complete loss of refrigerant, and equalization of the refrigerant system pressure with atmospheric pressure for a period longer than one hour. If even a
slight amount of positive refrigerant pressure is present in the system before repairs are carried out, the suction accumulator should not be replaced.
The suction accumulator is mounted to the RH inner fender to the right of the battery. The inlet tube of the suction accumulator attaches directly to the
evaporator core outlet tube and the outlet tube of the suction accumulator attaches to the compressor suction line.
After entering the inlet of the suction accumulator, heavier oil-laden refrigerant contacts an internally mounted dome (which serves as an umbrella) and
drips down onto the bottom of the canister.
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A small diameter oil bleed hole, in the bottom of the vapor return tube, allows the accumulated heavier liquid refrigerant and oil mixture to
re-enter the compressor suction line at a controlled rate.
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As the heavier mixture passes through the small diameter liquid bleed hole, it has a second chance to vaporize and recirculate through the A/C
compressor without causing compressor damage due to slugging.
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A fine mesh screened filter fits tightly around the bottom of the vapor return tube to filter out refrigerant system contaminant particles.
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A desiccant bag is mounted inside the canister to absorb any moisture which may be in the refrigerant system.
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A fitting located on the top of the suction accumulator is used to attach the A/C cycling switch. A long-travel Schrader-type valve stem core is
installed in the fitting so that the A/C cycling switch can be removed without recovering the refrigerant.
