2005 Ford F250 Diesel Supplement 3rd Printing - Page 10

Instrumentation Air filter restriction gauge (if equipped) The restriction gauge, located on the upper housing of the air cleaner assembly, measures the vacuum inside the air cleaner. The more the air cleaner is restricted (dirty, clogged), the higher the vacuum reading Check the air filter restriction gauge whenever the hood is raised to perform general engine maintenance at least every 7,500 miles (12,000 km). If the vehicle is operated in extremely dusty conditions, check the gauge at least every 500 miles (800 km), or two weeks, whichever comes first. Change the air filter when the gauge reads 25 inches (635 mm). Engine performance and fuel economy are adversely affected when the maximum restriction is reached. Blowing-out the air filter element with compressed air is not recommended as the compressed air may damage the filter paper. Note: It is not possible to determine the level of filter clogging by visual appearance alone. A filter which appears to be dirty may actually have several thousand miles (kilometers) of life remaining. Always use the underhood air filter restriction gauge to determine when the air filter element needs to be changed. The warning light on the instrument cluster should not be used exclusively for determining when the air filter element needs changing. 10 2005 Econoline (eco) Supplement USA (fus)