Operate the engine to activate the air compressor.
If the air compressor is not pumping, the unloader valve is
malfunctioning, and must be repaired or replaced.
Holset QE Models
The unloader body is installed with spring
tension. Use care when removing to prevent
personal injury. Always wear protective eye
Hold the unloader valve body down and remove the four
Remove the unloader valve spring.
Remove the unloader valve cap.
Remove the unloader body gasket and unloader valve
cap rectangular ring seal.
Do not use caustic cleaners.
Remove all carbon and varnish from the unloader valve