Toro 00075SL, Service Manual

Page: 55 / 290

Hydraulic
System
Reelmaster 5500-D Hydraulic System (Rev. C) Page 4 - 17
Raise Cutting Units
A three section, gear pump is driven off the PTO output
shaft of the hydrostatic transmission. Pump section (P3)
provides oil flow through the steering control valve and
lift manifold to all five cutting unit lift cylinders. Maximum
circuit pressure (1450 PSI) is limited by a relief valve in
the gear pump.
When the cutting units are in the lowered position, flow
from the gear pump (P3) passes through the steering
control valve and into the lift manifold. All lift manifold so-
lenoid valves are de-energized and flow is directed to
the hydraulic reservoir.
To raise the cutting units, solenoid valves (SV3), (SV4),
and (SV5) energize along with solenoid valve (SV1). So-
lenoid valve (SV2) is also energized, and directs oil flow
to the rod end of the lift cylinders. Hydraulic pressure
against the rod side of the cylinder causes the shafts to
retract, and raise the cutting units. When the solenoids
are deenergized, the lift cylinders are held in the raised
position.
The lift circuit includes a flow divider that provides for
even lifting of the front, outer cutting units (#4 and #5).
Pressure to the lift manifold can be monitored at port
(G3).