F 450 2WD Super Duty V8-6.4L DSL Turbo (2008)
Valve Piston
^ The valve piston is utilized for one main purpose:
1) It transfers the up and down movement from the Piezo Actuator to the Valve Mushroom.
Valve Mushroom, Return Spring, and Control Piston
^ The valve mushroom is a hydraulic check valve that allows high pressure fuel to bleed off into the fuel return passage directly above it whenever the
Piezo Actuator is energized.