Toro Pro Sweep 07066, Service Manual

Page: 27 / 103

Pro Sweep Hydraulic System Page 3 -- 11
Sweeper Raise/Hopper Dump 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.
10).
Sweeper Raise
When the tow vehicle hydraulics are engaged and the
remote transmitter sweeper up button is pressed and
held, solenoid valve SV3 in the hydraulic control man-
ifold is energized. The valve shift of SV3 directs oil flow
past the check valve in de--energized valve SV2, out of
control manifold port C and to the lift cylinder. Hydraulic
pressure against the lift cylinder piston extends the cyl-
inder to raise the hopper. The check valve fitting at-
tached to the lift cylinder allows oil flow to bypass the
orifice in the fitting for proper lift cylinder extension.
As the hopper is being raised, control manifold relief
valve RV functions as a circuit relief valve. If circuit pres-
sure reaches 2000 PSI (138 bar) while the sweeper is
being raised, RV will shift to reduce circuit pressure.
When the transmitter sweeper up button is released or
when the sweeper gets to transport (sweeper not offset)
or turn around (sweeper is offset) height, solenoid valve
SV3 in the hydraulic manifold is de--energized, stopping
the raise function. The check valve in de--energized
valve SV2 prevents oil flow from the lift cylinder so the
sweeper remains in the raised position.
Hopper Dump
If the sweeper is in the transport height position (sweep-
er not offset), the remote transmitter dump sequence is
entered and then the hopper dump button is pressed
and held, the sweeper hopper will fully raise to empty the
hopper. Control manifold solenoid valve SV3 is ener-
gized to allow oil flow to the lift cylinder. De--energized
valve SV2 and relief valve RV function the same to dump
the hopper as during the sweeper raise function.
Figure 10
CONTROL
MANIFOLD
LIFT
CYLINDER
OFFSET
CYLINDER
(DE--ENERGIZED)
Hydraulic System