Oil Filter Assembly

TM 9-2520-249-34&P

Figure 2-1. Hydraulic system oil supply components-schematic view.

a. Input-driven Pressure Pump. When the

The pump then forces the coolant to the areas of the

steer clutches, reverse clutches, and brake disks.

vehicle engine is operating, the input pressure pump

(fig. 2-13). When no coolant requirement exists. air is

draws oil from the transmission sump and delivers it to

admitted to the inlet side of the pump. The pump then

the cavity surrounding the filter element.

draws air into the circuit, and the coolant oil returns to

b. Output-driven Pressure Pump. When the

the sump.

vehicle is traveling forward, the output-driven pump also

draws oil from the sump and assists the input-driven

pump in satisfying system requirements. When the right

2-31. Oil Filter Assembly

track of the vehicle is driving in reverse, a spring-loaded

Oil delivered by either the input-driven pump and/or the

check valve in the line on the pressure side of the pump

output-driven pump flows through the filter element and

prevents backpumping.

into the main-pressure line.

If the filter element

c. Brake Coolant Pump. The brake coolant

becomes clogged, system pressure is maintained by a

pump operates any time a range clutch is engaged and

bypass valve in the top of the filter assembly. The

the vehicle is moving, but pumps oil only when the

bypass valve opens at 56 psi pressure differential and

vehicle is being steered or braked. During these

allows the oil to flow from the pumps directly to the

operations, sump oil is drawn into the pump through a

main-pressure line.

pair of large, mesh screens which cover the intake ports,

and a pair of disk-type, spring-loaded check valves.

2-12