Hartzell HC-E3YR-7 Owner's Manual page 138

J. Examine each of the four A-3147-3 studs for damage or
corrosion.
(1) Remove and replace any stud that is damaged or
corroded.
K. Use a plastic tool to remove remaining gasket material that is
on the governor unit base, either side of the pressure control
unit, or the governor mounting pad surface on the engine.
INSTALLATION AND REMOVAL
Propeller Owner's Manual
136
61-00-36
Page 3-62
Rev. 2 Feb/17