Toro Groundsmaster 4500-D Series Service Manual page 136

PTO Disengaged (continued)
PTO Engaged
Hydraulic System: Hydraulic Flow Diagrams
g308182
DECK CONTROL MANIFOLD (GM4700-D)
When the PTO switch is turned ON with the decks lowered, the solenoid valves
(PRV1 and PRV2) are energized with outputs from the TEC controller (T1). The
energized valves shift to direct pump flow toward the deck motors. As circuit
pressure to the deck motors increases, the brake relief cartridge (RV) opens
which allows an oil flow through the manifold orifice positioned before the logic
cartridge (LC). This flow creates a pressure increase at the logic cartridge that
will shift the logic cartridge and allow oil return from the deck motors.
On the Groundsmaster 4700-D
the PTO switch is ON, the deck control manifold solenoid valve (SV1/SV2) will
be energized by the TEC controller. This energized solenoid valve allows oil flow
to the appropriate deck motor as described above.
Maximum mow circuit pressure is limited at each deck manifold circuit by the
proportional relief valve (PRV1/PRV2). The deck relief valve pressure is 241
bar (3500 PSI). Mow circuit pressure can be measured at port G1 or G3 of the
deck control manifold.
The brake relief and logic cartridges control the stopping rate of the blades when
the solenoid valves are de-energized as the PTO switch is turned OFF or if the
decks are raised (see Cutting Deck Blade Braking (page
Figure 51
(Figure 51), if deck 6 or deck 7 is lowered and
Page 5–34
5–35)).
Groundsmaster ® 4500-D/4700-D
19245SL Rev A