Service Manual User Manual

CROWD (Boom In-Out) CIRCUIT
The crowd circuit allows the operator to extend and
retract the boom sections a total of 18 feet. Nine foot
extension is obtained from the movement of a
hydraulic cylinder joined to the first section and the
second section. Movement of the 2nd section and a
combination of cables and sheaves moves the 3rd
section.
The control lever is the same as used to raise and
lower the boom, but for the crowd the operator
moves it to the right and left. Moving it to the right
the booms.
Oil from the 3rd valve section routes the oil to the
base of the crowd cylinder. A counterbalance valve
is used on the cylinder for protection and speed
control.
GRADALL LOED MATERIAL HANDLER 534B SYSTEM OPERATION
AUXILIARY HYDRAULIC SYSTEM
When the 534B is equipped with a truss boom and
hydraulic winch, an additional control valve section
is added between the Sway Valve section and the Tilt
Valve section. The oil is routed from the control
valve up thru the boom to power the winch on the
truss boom.
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