Theory of Operation
Pressure oil not used by the swing function flows
Actuating the swing and boom up in combined
through the power passage (D) and boom II valve (I).
operation (J) shifts the swing valve (E), boom I valve
The pressure oil combines with the pressure oil from
(B), and boom II valve (I).
the front pump and flows to the boom cylinders. The
boom is raised by combined oil flow from the front and
Pressure oil from the front pump (F) flows through the
power passage (A) and boom I valve and out to the
boom cylinders (C) to raise the boom. At the same
time pressure oil from the rear pump (G) flows through
the swing valve (E) and out to the swing motor to
swing the upperstructure.