2011 Ford F350 Super Duty Regular Cab Diesel Supplement 5th Printing - Page 51
2011 Ford F350 Super Duty Regular Cab Manual
Page 51 highlights
Maintenance and Specifications AIR FILTER RESTRICTION GAUGE AND AIR FILTER REPLACEMENT Air filter restriction gauge: The restriction gauge, located on the upper housing of the air filter assembly, measures the vacuum inside the air filter. The more the air filter 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 and reset the gauge at least every 500 miles (800 km), or two weeks, whichever comes first. Change the air filter when the gauge reads near the "change filter" line and the chamber is filled with yellow. 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. Use the underhood air filter restriction gauge to determine when the air filter element needs to be changed. 51 2011 Diesel (eco) Supplement, 5th Printing USA (fus)