SEAL 7X9866 - Caterpillar

Probable Causes
Incorrect engine oil
Contaminated engine oil
Contaminated air
Contaminated fuel
Low oil pressureRecommended Actions
Incorrect Engine Oil
Use engine oil that is recommended and change the engine oil at the interval that is recommended by the engine's Operation and Maintenance Manual.Contaminated Engine Oil
Drain the crankcase and refill the crankcase with clean engine oil. Install new engine oil filters. Refer to the engine's Operation and Maintenance Manual.If the oil filter bypass valve is open, the oil will not be filtered. Check the oil filter bypass valve for a weak spring or for a broken spring. If the spring is broken, replace the spring. Refer to the engine's Disassembly and Assembly manual. Make sure that the oil bypass valve is operating correctly.Contaminated Air
Inspect the air inlet system for leaks. Inspect all of the gaskets and the connections. Repair any leaks.Inspect the air filter. Replace the air filter, if necessary.Contaminated Fuel
Inspect the fuel filter. Replace the fuel filter, if necessary.Contaminants in the fuel such as hydrogen sulfide and sulfur can lead to the formation of acids in the crankcase. Obtain a fuel analysis.Low Oil Pressure
When some components of the engine show bearing wear in a short time, the cause can be a restriction in a passage for engine oil.An indicator for the engine oil pressure may indicate sufficient pressure, but a component is worn due to a lack of lubrication. In such a case, look at the passage for the engine oil supply to the component. Refer to the Systems Operation/Testing and Adjusting manual.