TM 5-3805-281-24-1
Theory of Operation
Actuating the left (I) or right (H) propel functions blocks
Pushing the power boost switch (B) sends an electrical
the flow of pilot oil through the propel pilot signal
signal from the engine and pump controller (A) to
passage (G) causing the pilot oil control signal in the
energize the power boost solenoid valve (J) coil. The
signal passage to increase. The increased control
solenoid valve shifts sending a pilot oil control signal
signal flows through the shuttle valve (D) to the system
through the shuttle valve (D) to the system relief valve
relief valve (C). The control signal pushes the piston in
(C). The control signal pushes the piston in the system
the system relief valve down increasing the pressure
relief valve down increasing the pressure setting. The
setting. The main hydraulic system now operates at
main hydraulic system now operates at a higher
the higher operating pressure as long as the propel
operating pressure for approximately 8 seconds. (See
functions are actuated. The increased pilot oil control
System Relief Valve and Power Boost Operation in
signal from the propel pilot signal passage also closes
this group.)
the propel pressure switch (E) sending an electrical
signal to the engine and pump controller.
The power boost solenoid valve is also actuated in
precision work mode when the boom up function is
actuated.
CED,TX08227,3121
1911MAY982/2
9025
05
50
6-49
