BODY 3723740 - Caterpillar

Family Of EnginesThe engines should be prelubed prior to rotating the engine crankshaft with the barring group. The prelube pump should also be left on during the time the engine crankshaft is rotated.
The lube oil can drain out from between the crankshaft and engine bearings if the engine has not been run for a period of time. Damage can result if the crankshaft is rotated on dry bearing surfaces.
It is particularly important to prelube the engine after shipping, after prolonged storage, during initial installation operations, and any time the crankshaft may be rotated several times, such as during the alignment of the driven equipment.
Prelubing the engine is recommended when the crankshaft is rotated during normal maintenance operations. This includes adjusting valves and setting injector timing.
The intermittent prelube pump should not be operated continuously for extended periods of time. If, during repairs, the intermittent prelube pump has run continuously for a period of three hours or more, it will be necessary to remove any oil that may have collected in the cylinders and/or above the valves.The oil can be removed from the cylinders by using the following procedure.
1. Remove the cylinder pressure plugs from the cylinder head. DO NOT use the air or electric starters to rotate the engine. If the engine is rotated too fast, oil cannot flow through the openings in the cylinder head fast enough to prevent damage to the combustion seal.2. Slowly rotate the engine by hand using the barring device to determine which cylinders have lubricating oil in them. Rotate the engine a minimum of four revolutions, or until there is no sign of oil leaving the cylinder heads.3. The cylinders that had oil in them must have the oil removed from the cavity in the top of the pistons. This can be done by removing the unit injector group from the cylinder. Then the oil can be extracted from the cylinder.4. Install the cylinder pressure plugs.