Seville STS V8-4.6L VIN 9 (1998)
Expansion Block/Orifice Tube: Description and Operation
The plastic expansion (orifice) tube (2) is made of a mesh-screen (1) and orifice (3). The expansion (orifice) tube is located in the evaporator inlet pipe at
the liquid line connection. The tube restricts the high pressure liquid refrigerant in the liquid line. Metering the refrigerant flow to the evaporator as a low
pressure liquid. The expansion tube and orifice have filter screens which protect from contamination on both the inlet and outlet sides of the tube. The
expansion tube is sealed inside the refrigerant pipe by an O-ring. This O-ring is necessary for proper operation of the refrigerant system. When the
engine is OFF and the A/C is running, the refrigerant in the system flows from the high pressure side of the tube to the low pressure side until the
pressure is equalized. This may be detected as a faint hissing sound for 30-60 seconds and is a normal condition.
