Service Manual User Manual

SWAY CIRCUIT
The sway circuit permits the operator to level the
main frame of the machine in relation to the position
of the front axle. With the sway cylinder the operator
can tilt the frame up to 8° in either direction from
horizontal. Movement of the sway lever to the right
or left actuates a plunger in the first control valve
section, and oil is routed to the sway cylinder, and
the machine sways right or left.
There is a bubble level in the cab to assist the
operator in determining when the frame and boom
is level.
LIFT CIRCUIT
The lift circuit allows the operator to raise the boom
assembly up 70ø and lower it to a -4° angle.
Movement of the boom control lever back, raises
the boom and a forward motion, lowers the boom.
An angle indicator is located on the left side of the
main boom section.
At the base of both lift cylinders is a counterbalance
valve. The valves serve as a lock-out valve to hold oil
in the cylinder should a hose break or to prevent
boom movement should the lever be actuated while
the engine is shut off. It also serves as a flow valve to
control the downward movement of the boom at a
controlled speed.
The 534B-6 models have 4½” cylinder. The 534B-8
models have 5" cylinder.
GRADALL LOED MATERIAL HANDLER 534B SYSTEM OPERATION
12