Toro Sand Pro 3040 Service Manual page 90

Lift Valve in the Neutral Position
Lift Valve in the Raise Position
Lift Valve in the Lower Position
Lift Valve in the Float Position
Hydraulic System: Hydraulic Flow Diagrams
The implement/charge pump (P2) is a fixed displacement gerotor pump that is
part of the traction pump. The implement/charge pump also supplies fluid flow
for the lift circuit and the charge circuit of the closed loop traction system for both
model 08743 and 08745 machines. The implement/charge pump also supplies
fluid flow to the steering circuit on model 08745 machines. On model 08745
machines, the pump output flows to the steering control valve before supplying
the lift and charge circuit needs so that the steering circuit has priority.
On model 08743 machines, the steering and lift circuit pressure is limited to
5,171 kPa (750 psi) by a relief valve in a remote manifold located near the lift
valve. On model 08745 machines, the steering and lift circuit pressure is limited
to 5,171 kPa (750 psi) by a relief valve located in the steering valve.
The lift valve has 4 separate operating positions: N
F . The standard rear lift valve and the optional front lift valve operate the
LOAT
same.
When the lift lever is in the N
raising, lowering or floating. Hydraulic fluid flow from the implement/charge
pump bypasses the lift cylinder through the lift valve in the N
The Hydraulic fluid returns to the tank as a normal part of the charge, case drain,
and bleed off circuits.
Moving the lift lever to the R
flow from the implement/charge pump to the rod end of the lift cylinder. The
piston moves into the cylinder pushing fluid from the cap end of the cylinder and
to the tank. As the cylinder rod retracts, the attachment is raised. When the
cylinder reaches the end of its stroke, or if the lift mechanism is prevented from
raising, the relief valve in the steering valve opens and directs the hydraulic
flow out the steering valve T port to the oil cooler until the lift lever is released.
When the lift lever is released, the lift valve returns to the neutral position. The
attachment is held in position by check valves in the lift valve.
Moving the lift lever to the L
fluid flow from the implement/charge pump to the cap end of the lift cylinder. The
piston moves out of the cylinder pushing fluid from the rod end of the cylinder and
to the tank. As the cylinder rod extends, the attachment is lowered. When the
cylinder reaches the end of its stroke, or if the lift mechanism is prevented from
lowering, the relief valve in the steering valve opens and directs the hydraulic
flow out the steering valve T port to the oil cooler until the lift lever is released.
When the lift lever is released, the lift valve returns to the neutral position. The
attachment is held in position by check valves in the lift valve.
As an attachment moves over terrain with changing elevation, the lift mechanism
should be allowed to move up and down (float) to follow ground contours during
operation. After the attachment is fully lowered, and the lift lever is moved to the
F position, a path is open in the lift valve for fluid at both ends of the lift
LOAT
cylinder to flow in either direction if necessary. An adjustable detent plate allows
the lift lever to be held in the float position; refer to the traction unit Operator's
Manual to adjust the lift lever detent plate.
position, the lift system is not actively
EUTRAL
position allows the lift control valve to direct fluid
AISE
position allows the lift control valve to direct
OWER
Page 5–20
, R , L , and
EUTRAL AISE OWER
position.
EUTRAL
Sand Pro ® 3040 and 5040
20251SL Rev A