TM 5-3805-281-24-1
Theory of Operation
PROPEL FLOW CONTROL VALVE OPERATION
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than what is needed to raise the boom. Therefore the
The function of propel flow control valve (I and J) is to
pressure oil from the rear pump by the power passage
restrict rear pump supply oil flow through the power
(F) will flow to the lower pressure side of the left propel
passage (F) to the left propel valve (C) during
valve and not to the higher pressure side of boom II
combined operation of propel and boom up functions.
valve.
Actuating a dig function opens the flow combiner valve
Actuating the boom up function also sends the boom
(E) so when used in combined operations with propel
up pilot pressure signal (A) to the piston (G) in the
function supply oil from front pump goes to the propel
propel flow control valve. The piston is pushed to the
valves and supply oil from the rear pump goes to the
right increasing the pressure on the poppet (D) by the
swing, arm, and boom functions. (See Flow Combiner
spring. The poppet restricts the flow of supply oil from
Valve Operation in this group.)
the power passage to the left propel valve to ensure
there is enough pressure at the boom II valve for
When traveling on level ground or down a slope, the
boom up operation.
pressure to turn the propel motors can becomes less
Continued on next page
CED,TX08227,3169
1904JUN981/2
