A/C Cylinder Head (QE Models) (012-104)
B3.9 and B5.9 Series Engines
Section 12 - Compressed Air System - Group 12
E-Type Air Compressor
unloader can be identified by the letter "E" (SS296E, and
SS338E) and by the caution on the dataplate.
equipped with the E-Type unloader.
E-Type System with Air Dryer
Vehicles equipped with air dryers vented to the atmosphere
during unloaded compressor operation, using the Holset
-Type air compressor, require the installation of an econ
valve to prevent excessive oil consumption.
NOTE: Some air dryers can have a built-in econ valve.
Check with the manufacturer as to which type is installed.
E-Type System without Air Dryer
Air systems without air dryers, or with air dryers not vented
to the atmosphere during unloaded compressor operation,
can use the Holset E-Type unloader valve without modify-
ing the air system.