Lumina L4-151 2.5L (1991)
Expansion Block/Orifice Tube: Description and Operation
A/C System - Typical
DESCRIPTION
The plastic expansion tube, with its mesh screen and orifice, is located between the condenser outlet and evaporator inlet. It provides a restriction to
the high- pressure liquid refrigerant in the liquid line, metering the flow of refrigerant to the evaporator as a low- pressure liquid. The expansion tube
and orifice are protected from contamination by filter screens on both inlet and outlet sides.
Restricted Expansion Tube
When system diagnostics indicate a restricted expansion tube, it may not be necessary to replace the tube assembly. Metal chips, flakes or slivers
found on the screen may be removed with shop air and the tube may be reused. Refer to Service and Repair for conditions which require
expansion tube replacement.
