Toro Pro Sweep 07066 Service Manual page 29

Sweeper Lower Circuits
NOTE: Hydraulic flow and relief pressure to the Pro
Sweep are determined by the tow vehicle.
When the tow vehicle hydraulics are engaged for the
sweeper, hydraulic flow from the tow vehicle goes to the
sweeper control manifold (port P) through the hydraulic
inlet hose. If the sweeper brush motor is not engaged
(sweeper is raised above the transport height) and the
lift and offset cylinders are stationary, hydraulic flow
from the tow vehicle is directed by the control manifold
pressure compensator valve EC and the de--energized
solenoid valve SRV to return to the tow vehicle through
control manifold port T and the return to tank hose (Fig.
11).
Sweeper Lower
When the remote transmitter sweeper down button is
pressed, solenoid valve SV2 in the hydraulic control
manifold is energized. The valve shift of SV2 allows a
path for oil flow from the lift cylinder. The weight of the
dump hopper and sweeper frame cause the lift cylinder
to retract, allowing the sweeper to lower to the ground.
The orifice in the lift cylinder check valve fitting restricts
oil flow from the cylinder to control lift cylinder retraction
speed.
While lowering, if the remote transmitter sweeper up or
stop button are pressed, solenoid valve SV2 will de--en-
ergize and oil flow from the lift cylinder will cease. The
sweeper will stop lowering and remain in position.
As the sweeper is being lowered, relief valve RV func-
tions as a circuit relief valve. If circuit pressure reaches
2000 PSI (138 bar), RV will shift to reduce circuit pres-
sure.
Sweeper Float
After the sweeper has been fully lowered to the ground,
solenoid valve SV2 will continue to be energized. The
shifted valve will allow lift cylinder and sweeper move-
ment so the sweeper head can follow ground surface
contours.
Pro Sweep
OFFSET
CYLINDER
Page 3 - - 13
LIFT
CYLINDER
CONTROL
MANIFOLD
(DE--ENERGIZED)
Figure 11
Hydraulic System