Lift Circuit: Raise - Toro Groundsmaster 360 Service Manual

Lift Circuit: Raise (Fig. 15)
A single section gear pump is directly coupled to the
transmission which is driven by the engine. This gear
pump supplies hydraulic flow for both the steering and
lift/lower circuits. Gear pump flow is routed to the steer-
ing control valve first so the steering circuit has priority.
The pump takes its suction from the hydraulic tank.
When the deck lift switch is in its neutral state, flow from
the gear pump bypasses the lift cylinder and is routed
through the deck lift manifold directly to the oil cooler and
then to the transmission. The transmission case drain
allows oil to return to the hydraulic tank.
NOTE: If the deck lift switch is pressed to the RAISE
position while the steering wheel is being turned, lift
speed will be reduced.
NOTE: The engine must be running to allow the cutting
deck to be raised. When the rear of the lift switch is de-
pressed and held, the deck will raise. If the switch is re-
leased when raising the deck, the deck will stop raising
and remain in position.
When the deck lift switch is pressed to the RAISE posi-
tion and held, both solenoid valves (A and B) in the deck
lift manifold are energized to cause the valves to shift.
Energized solenoid valve B prevents gear pump flow
from bypassing the lift cylinder. Energized solenoid
valve A allows hydraulic flow from the gear pump to the
barrel end of the lift cylinder. The lift cylinder extends,
causing the cutting deck to raise. The fluid displaced
from the rod end of the lift cylinder is routed to the oil
cooler, transmission and then to the hydraulic tank. An
orifice fitting at the barrel end of the lift cylinder controls
the extending speed of the lift cylinder while raising the
cutting deck.
Groundsmaster 360
Load on the lift cylinder causes lift circuit pressure to in-
crease. If lift circuit pressure reaches 1800 PSI (125
bar), the relief valve in the gear pump shifts to allow
pump flow to return to the hydraulic tank.
When the deck lift switch is released from RAISE, both
solenoid valves (A and B) in the deck lift manifold are
de--energized. De--energized solenoid valve B allows
gear pump flow to bypass the lift cylinder, returning to
the oil cooler, transmission and then to the hydraulic
tank. De--energized solenoid valve A prevents hydraulic
flow to and from the lift cylinder to keep the cutting deck
in the raised position.
Page 4 - - 19 Hydraulic System