CATERPILLAR DIESEL FUEL TIPS
* It’s possible for a secondary fuel filter to suck air, but not leak fuel when running. * Hook a sight glass where you think the engine is losing prime. When the engine is not running, air goes up & siphoning goes to highest point down. * A plugged fuel return line may cause low power, poor fuel mileage and excessive black smoke. An engine with this situation will usually have high fuel pressure and it will be hard to use the manual hand priming pump (Because of so much pressure). It will also cause high fuel temperature and will not be able to get rid of the air in the fuel. – * If fuel leaks out of the hand priming pump it should be replaced, because it could also be sucking air from this pump.

Tab (Shay) Leskovisek
Altorfer Power Systems
Bartonville, IL
June, 2015