caution - Toro

Raise Cutting Deck
A four section gear pump is coupled to the piston (traction)
pump. The third gear pump section supplies hydraulic
flow to the lift/lower control valve and the steering
control valve. Hydraulic flow from this pump section is
delivered to the two circuits through a proportional flow
divider. The gear pump takes its suction from the hydraulic
reservoir.
When the cutting deck is in a stationary position, flow
from the gear pump is by--passed through the lift/lower
control valve, counterbalance manifold, oil filter and
traction charge circuit.
To raise the cutting deck, the center lift lever on the lift/
lower control valve is pulled to allow valve shift in the lift/
lower control valve. This valve change allows hydraulic
pressure to the rod end of the front deck lift cylinders,
causing the cylinders to retract. As the cylinders retract,
the cutting deck raises. Oil from the piston end of the cylinders
returns to the hydraulic reservoir. When the lift lever
is released, the lift cylinders and cutting deck is held
in position.
To raise a wing deck, the appropriate lift lever on the lift/
lower control valve is pulled to allow valve shift in the lift/
lower control valve. This valve change allows hydraulic
pressure to the piston end of the wing deck lift cylinder
and causes the cylinder shaft to retract, raising the wing
deck. Oil from the rod end of the cylinder flows to the
traction charge circuit. When the lift lever is released, the
lift cylinder and wing deck is held in position.
An adjustable counterbalance valve (CB) in the counterbalance
manifold maintains back pressure on the deck
lift cylinders to allow some of the cutting deck weight to
be transferred to the traction unit to improve traction. A
relief valve located in the lift/lower control valve limits lift/
lower circuit pressure to 1500 PSI (103 bar). Excess circuit
flow is routed to the oil filter and then to the traction
charge circuit.
Hydraulic
System
Groundsmaster 4100--D
Page 4 - 17
Hydraulic System