RIM AS 8R1422 - Caterpillar

Caterpillar Machines With Engines Equipped With Primary And Secondary Fuel FiltersResources may be unnecessarily focused on other possible fuel system components if fuel filter blockage is overlooked. Fuel filter blockage can occur on any engine, at any time, if fuel contamination exists upstream of the fuel filters. Symptoms of blocked fuel filters include low power and/or erratic fuel pressure. Even if the filters have just been changed, fuel contamination could rapidly block the new filters.
When troubleshooting low power, intermittent low power or erratic fuel pressure symptoms, it can be helpful to measure the vacuum on the inlet and outlet ports of the primary fuel filter. Any point in the inlet side of the fuel system (before the fuel transfer pump) which measures 8 inches of mercury vacuum or more restriction should be cleared before further work is done to resolve the performance problem. Areas to check include:* Fuel lines (clear with compressed air). * Fuel tank vent (clear with compressed air).* Primary fuel filter (remove and replace or clean).* Fuel contamination (Drain at least one gallon of fuel from the fuel tank drain valve into a bucket. Check to be sure no contaminants are present in the drained fuel.)