ARMY TM 9-6115-604-12
NAVY NAVFAC P-8-633-12
Working from the inside, use compressed air to blow out all loose dust from the primary element. Do not
hold the air nozzle closer than 1 Inch (25.4 mm) to the inner surface of the filter element and do not
exceed 30 psi (207 kPa) air pressure.
Hold a light (at least 60 W) Inside the primary element assembly (35) and look through the element from
the outside, and check for breaks, punctures, or tears in the filter paper. Replace the element If it is
If inspection shows the primary element assembly (35) to be sound, clean the element as follows:
To avoid engine contamination and improper operation do not clean the safety element
assemblies. The safety elements should be replaced when the Indicator assembly shows red,
after three servicings or changes of the primary element assembly (35) or after 1 year regardless
of the safety signal indication. The primary element assemblies may be serviced and cleaned up
to six times.
In a container of sufficient size to completely submerge the primary element assembly (35), mix a
cleaning solution using 1 ounce (28.4g) of non-sudsing, synthetic detergent, such as A-A-1 376, for
each 2 gallons (7 6 liters) of water Do not use hot water.
Submerge the element In the cleaning solution, and add more solution as necessary to completely
submerge the element.
Allow the element to soak for at least 15 minutes. During the soaking period, turn and gently agitate
the element occasionally to aid the cleaning action.
To avoid damage to the element, water pressure must not exceed 40 psi (275 kPa), and the flow
must be unrestricted. Do not use a nozzle on the end of the hose.
Remove the element from the cleaning solution, and rinse thoroughly, inside and out, with running
To avoid damage to the element, heated air used for drying must not exceed 160°F (71°C). Do
not use any other form of heat to dry the element. Do not dry with co mpressed air.
Allow the element to air dry. Heated air, not to exceed 160°F (71 °C), may be gently circulated
through the element to speed drying, If available. Do not use compressed air.
After drying, examine the element for breaks, punctures, or tears In the filter paper In accordance with
step (g), above.
(i) Reset the air restriction indicator assemblies (Figure 1-5) by pressing the reset button on top of the
indicator. If the indicator will not reset properly, replace indicator In accordance with paragraph 4-77.
To avoid damage to the safety signal indicators, do not use compressed air over 30 psi (207 kPa)
(j) If removed, reset the safety signal indicator in the nut assembly (33, Figure 4-49) by blocking the outer
hole, and pressurizing the Inner hole with 30 psi (207 kPa) air. Replace the nut assembly If the Indicator
will not reset properly.