Service Manual

Workman HD SeriesPage 9 − 14Hydraulic System
High Flow Hydraulic Circuit
On Workman HDX and HDX−D vehicles that are
equipped with the high flow hydraulics kit, a second gear
pump is directly coupled to the standard gear pump. This
second gear pump provides hydraulic system flow for
the high flow circuit that is designed to power hydraulic
attachments. A manifold equipped with a solenoid oper-
ated relief valve (SVRV) is used to control the circuit and
when energized, also provides circuit relief. A dash
mounted rocker switch is used to energize the solenoid
to engage the circuit. The high flow circuit includes quick
disconnect couplers for attachment connection, a reser-
voir, a hydraulic filter and an oil cooler.
High Flow Circuit OFF
When the rocker switch is in the OFF position, the man-
ifold solenoid operated relief valve (SVRV) is not ener-
gized. Flow from the gear pump is routed through the
manifold, the oil cooler, the oil filter and then returns to
the reservoir.
High Flow Circuit ON (Fig. 15)
When the rocker switch is in the ON position, the man-
ifold solenoid operated relief valve (SVRV) is energized.
The energized solenoid valve directs gear pump oil flow
to the hydraulic attachment. Circuit pressure is limited to
2000 PSI (138 bar) by the manifold solenoid relief valve
(SVRV). Return oil from the attachment is routed
through the oil cooler, the oil filter and then returns to the
reservoir.
Figure 15
ENERGIZED
SWITCH IN
ON POSITION
HYDRAULIC
ACCESSORY
MOTOR
HYDRAULIC
MANIFOLD
ROCKER