Lubrication
Instructions for the lubrication a system, equipment, component, or item.
Grease lubrication practices
DO NOT PURGE LUBRICATE THE HANGER BEARINGS OR THEY WILL BE OVER- GREASED. IF THIS OCCURS, THE BEARINGS WILL RUN HOTTER AND FOR A LONGER PERIOD OF TIME AND THESE CONDITIONS CAN CAUSE DAMAGE TO THE BEARING COMPONENTS.
DO NOT USE A HIGH CAPACITY/HIGH VELOCITY GREASE GUN TO GREASE LUBRICATE THE COMPONENTS. THE USE OF THIS EQUIPMENT CAN CAUSE DAMAGE TO THE COMPONENTS.
The following practices do not apply to the hanger bearings.
Obey the following grease lubrication practices:
Before and after a grease lubrication, visually examine the grease fittings to make sure that the spring loaded steel ball is visible. If the steel ball is not visible, does not go back to the closed position, the grease fitting shows excessive leakage, or it is difficult to apply grease during the lubrication, replace the grease fitting (BHT-ALL-SPM, Chapter 8).
If the grease fitting is replaced because the spring loaded steel ball was not visible, put a small steel probe into the back of the grease fitting and make sure that the steel ball is there. If the steel ball is not there, examine to make sure that the steel ball has not moved into the component and caused damage. Discard the grease fittings that have been removed.
Protect the grease lubricants from excessive temperature and humidity, and from contamination. See the posted shelf life, if applicable.
Before you use a supply of grease, whether in its original container or in dispensing equipment, make sure that no oil separation has occurred.
If oil separation occurred without loss (leakage) of oil, thoroughly remix the oil component with the thickening agent to restore the original load bearing capabilities. Use only clean tools for mixing.
Discard any grease supply that has lost some of its oil component after separation, whether in its original container or in grease dispensing equipment. Oil-depleted lubricants can be dangerous to the bearings.
Intermixing brands of grease within the same specification is not permitted. If you need to change the grease brand, purge to remove the old grease until there is only new grease visible, unless specified differently.
DO NOT USE HIGH PRESSURE WATER, STEAM, OR SOLVENT WASH WHEN YOU CLEAN THE ROTATING CONTROL BEARINGS. HIGH PRESSURE WILL FORCE WATER, SOLVENT, AND SOMETIMES FOREIGN PARTICLES INTO THE BEARING CAVITY.
Purge lubrication of a bearing means that new grease is injected in the bearing to remove the old grease.
Special lubrication practices
Obey the following special lubrication requirements:
After each day of operation in rain or after washing the main rotor hub, purge lubricate all the exposed control bearings to remove trapped moisture and to make sure that a lube film is applied to the applicable surface.
Before each flight, when the helicopter has been exposed to high ambient temperatures, purge lubricate the main rotor grips and the pillow blocks/trunnion to make sure that any grease that was separated will be replaced with fresh grease. This practice will prevent premature brinelling of the main rotor yoke bearing journals.
If the helicopter is parked outside in a heavy dew environment, purge lubricate all the exposed control bearings every 7 days. This practice will reduce the risk of moisture being trapped in voids.
If the helicopter has been, or will be, parked or stored for more than 45 days without operation or service, purge lubricate all the bearings. Same applies to spare components on the shelf.
After each wash, all the bearings exposed to the wash should be lubricated.
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