3500 4x2 Pickup L6-359 5.9L DSL Turbo (1994)
Air Filter Element: Testing and Inspection
Do not attempt to unnecessarily remove the top of the air filter housing for air filter element inspection on diesel engines.
Air Filter Restriction Gauge Location
The air filter housing is equipped with an air Filter Minder gauge. This air flow restriction gauge will determine when the filter element is restricted and
should be replaced.
Air Filter Restriction Gauge
The Filter Minder consists of a diaphragm and calibrated spring sealed inside of a plastic housing. A yellow colored disc attached to the diaphragm
moves along a graduated scale on the side of the Filter Minder. After the engine has been shut off, a ratcheting device located within the Filter Minder
will hold the yellow disc at the highest restriction that the filter element has experienced. A drop in air pressure due to a filter element restriction moves
the diaphragm and the yellow disc will indicate the size of the air drop.
CAUTION: Certain engine degreasers or cleaners may discolor or damage the plastic housing of the Filter Minder. Cover and tape the Filter Minder if
any engine degreasers or cleaners are to be used.
To test, turn the engine OFF. If the yellow disc has reached the red colored zone on the graduated scale, the filter element should be replaced.
RESETTING THE FILTER MINDER:
After the filter element has been replaced, press the rubber button on the top of the Filter Minder. This will allow the yellow colored disc to reset.
After the button has been pressed, the yellow disc should spring back to the UP position.
If the Filter Minder gauge has reached the red colored zone, and after an examination of the filter element, the element appears to be clean, the
high reading may be due to a temporary condition such as snow build-up at the air intake. Temporary high restrictions may also occur if the filter
element has gotten wet such as during a heavy rain or snow. If this occurs, allow the element to dry out during normal engine operation. Reset the
rubber button on the top of the Filter Minder and retest after the element has dried.
