F 150 2WD Pickup V8-4.6L (2002)
Accumulator HVAC: Description and Operation
NOTE: Installation of a new suction accumulator is not required when repairing the air conditioning system except when there is physical evidence of
system contamination from a failed A/C compressor or damage to the suction accumulator.
An A/C evaporator core orifice or O-ring seal is not considered a major component, but a new A/C evaporator core orifice must be installed whenever a
new A/C compressor is installed for lack of performance.
The suction accumulator is mounted on the A/C accumulator bracket to the right of the vehicle centerline. The inlet of the suction accumulator attaches
directly to the A/C evaporator core outlet tube and the outlet tube of the suction accumulator attaches to the A/C manifold and tube.
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.
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.
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.
A fine mesh screened filter fits tightly around the bottom of the vapor return tube to filter out refrigerant system contaminant particles.
A desiccant bag is mounted inside the canister to absorb any moisture which may be in the refrigerant system.
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 discharging the A/C system.