TM 5-3805-281-24-1
Theory of Operation
The propel flow control valve (N) is in the power
Supply oil from the front pump (O) flows to the right
passage (K) to block the flow of supply oil from the
control valve (B). Supply oil from the rear pump (P)
power passage to left propel (U) when propel and
flows to the left control valve (A).
boom up functions are used in combined operation.
(See Propel Flow Control Valve Operation in this
When all valve spools (D--G and Q--U) are in neutral,
group.)
supply oil flows through the neutral passages (C),
through the front (I) and rear (V) pump control valves
The bypass shut-off valve (J) is used with the auxiliary
and into the return passage (H). The left and right
(T) function to route front pump supply oil by an
control valves are open-center valves. Power
external line to the power passage at the auxiliary
passages (K) in the left and right control valves are
valve spool. (See Bypass Shut-Off Valve Operation in
used to route supply oil for the combined operation of
this group.)
functions.
The system relief valve (M) senses the operating
The flow combiner valve (L) is in the power passage
pressure in the neutral and power passages. The relief
(K) to route supply oil from the front pump (O) to both
valve will open to relieve excess pressure to the return
the right and left propel functions when used in
passage.
combined operation with the dig functions so the
machine travels straight. The rear pump supplies oil to
the dig functions. (See Flow Combiner Operation in
this group.)
CED,TX08227,3119
1905MAY982/2
9025
05
45
6-44
