TM 5-3810-306-20
Oil Filter
The oil filter assembly is located in the reservoir. The assembly housing contains a replaceable 10 micron filter element
through which most of the oil returning to the reservoir is directed. From a box manifold inside the reservoir, return oil
enters the outer annular passage in the filter body assembly and flows upward into the head assembly and down into the
center of the element. During normal operation, oil passes outward through, and is filtered by, the element and is
exhausted into the annular housing surrounding it and downward through a tube into the reservoir.
With a clogged filter, pressure builds inside the filter element and head assembly forcing the spring loaded valve in the
upper housing to unseat and bypass oil directly to the exhaust annulus. The white indicator post, normally visible in the
head assembly window, moves downward with the bypass valve providing visual indication, from outside, of the degree of
element blockage. Element bypass begins when internal pressure reaches 25 psi (172.4 kPa/1.72 bar). Total bypass is
indicated by the top of the white indicator bar reaching the halfway mark on the window.
Three Section Pump
Section one of the hydraulic pump supplies the valve bank housing the main hoist boost, auxiliary hoist, and lift boost
directional control valves. Oil flowing from the valve bank returns to the reservoir filter through the return manifold.
Section two of the hydraulic pump supplies the valve bank housing the main hoist and auxiliary hoist boost directional
control valves. Oil flowing from the valve bank returns to the reservoir filter through the return manifold.
Section three of the hydraulic pump supplies the valve bank housing the lift, rear steer, and telescope directional control
valves. Oil flowing from the valve bank returns to the reservoir control filter through the return manifold.
Two Section Pump
Section one of the hydraulic pump supplies the integrated outrigger valve, and subsequently the outrigger circuit. Pressure
beyond flow from the integrated outrigger valve supplies the swing valve bank which controls the rotation of the crane
superstructure.
Section two of the hydraulic pump supplies the rear axle lockout valve and the front steering control valve. Oil flowing from
the valves returns to the reservoir filter through the return manifold.
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