SHAFT 1271596 - Caterpillar

Crankcase Oil Level
Check the level of the oil in the crankcase. Add oil if oil is needed. It is possible for the oil level to be too far below the oil pump supply tube. This will cause the oil pump not to have the ability to supply enough lubrication to the engine components.This engine also uses a scavenge oil pump to move trapped oil from the rear of the engine back to the main sump at the front. Be sure that this oil pump operates correctly in order to maintain a sufficient oil level for the main oil pump supply tube.The Oil Pump Does Not Work Correctly
The inlet screen of the supply tube for the oil pump can have a restriction. This restriction will cause cavitation and a loss of oil pressure. Air leakage in the supply side of the oil pump will also cause cavitation and loss of oil pressure. If the bypass valve for the oil pump is held in the open position, the lubrication system can not reach the maximum pressure. Oil pump gears that have too much wear will cause a reduction in oil pressure.Oil Filter Bypass Valve
If the bypass valve for one or more of the oil filters is held in the open position due to a restriction, an increase in the oil pressure can be the result. Remove each bypass valve and clean each bypass valve in order to correct this problem. You must also clean each bypass valve bore. Install new Caterpillar oil filters. New filters will prevent more debris from causing this problem.Too Much Clearance At Engine Bearings Or Open Lubrication System
Components that are worn and components that have too much bearing clearance can cause low oil pressure. Low oil pressure can also be caused by an oil line or an oil passage that is open, broken, or disconnected.Piston Cooling Jets
When the engine is operating, piston cooling jets direct oil toward the bottom of the piston in order to cool the piston. This also provides lubrication for the piston pin. If a jet is broken, plugged, or installed incorrectly, a seizure of the piston will occur quickly.