The following are definitions of the types/classes of leakage you need to know to be able to determine the status
of your equipment.
Seepage of fluid (as indicated by wetness or discoloration) not great enough to form
Leakage of fluid great enough to form drops, but not enough to cause drops to drip from
the item being checked/inspected.
Leakage of fluid great enough to form drops that fall from the item being
Equipment operation is allowable with minor
leakage (Class I or II). Of course consideration
must be given to the fluid capacity in the
item/system being checked/inspected. When
operating with Class I or II leaks, continue to
check fluid levels as required on your PMCS.
Class II leaks should be reported to your
The items listed in the table indicate the minimum inspection requirements. Perform at the intervals shown below:
Do your (M) PREVENTIVE MAINTENANCE monthly (once a month).
Do your (Q) PREVENTIVE MAINTENANCE quarterly (every three months).
Do your (S) PREVENTIVE MAINTENANCE semi-annually (every six months).
Do your (A) PREVENTIVE MAINTENANCE annually (once every year).
Do your (B) PREVENTIVE MAINTENANCE bi-annually (once every two years).
Do your (H) PREVENTIVE MAINTENANCE at the hour interval listed.