Removing Spark Plug Frozen To Bushing - Piper PA-44-180 SEMINOLE Maintenance Manual

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When withdrawing the ignition cable lead connection from the plug, care must be
taken to pull the lead straight out and in line with the center line of the plug barrel;
otherwise a side load win be applied, which frequently results in damage to the barrel
insulator and connector. If the lead cannot be removed easily in this manner, the
resisting contact between the neoprene collar and the barrel insulator will be broken
by a rotary twisting of the collar. Avoid undue distortion of the collar and possible
side loading of the barrel insulator.
2. Remove the spark plug from the engine. In the course of engine operation, carbon and other combustion
products will be deposited on the end of the spark plug and will penetrate the lower threads to some degree.
As a result, greater torque is frequently required for removing a plug than for its installation. Accordingly,
the torque limitations given do not apply to plug removal and sufficient torque must be used to unscrew the
plug. The higher torque in removal is not as detrimental as in installation, since it cannot stretch the
threaded section. It does, however, impose a shearing load on this section and may, if sufficiently severe,
produce a failure in this location.
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
Figure 74-32. Removing Spark Plug Frozen to Bushing
— Note —
3G19
7 4 - 2 2 - 0 1
Page 74-26
Revised: May 15, 1989