DIESEL PLUGGED FUEL FILTER FILTER CHECKING PROCEDURE

A new diesel engine fuel filter cannot be checked for a plugged condition by simply blowing through it with your mouth. During the manufacturing process a percentage of the filters are checked with a light petroleum product. Air will not pass through a wet filter element as easily as one that is dry. Therefore, blowing through the filter with your mouth cannot be used as a test to determine if the filter element is plugged. Installation on the engine or regulated air pressure of 2-3 PSI is the only way to determine if the filter is plugged. Care should be taken not to use excessive air pressure when checking the filter or damage to the filter element can occur.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.