Lower Cutting Units - Toro Reelmaster 5200-D Service Manual

Lower Cuttings Units
A three section, gear pump is driven off the PTO output
shaft of the hydrostatic transmission. Pump section (P3)
provides oil flow through the steering control valve and
hydraulic manifolds to all five cutting unit lift cylinders.
Maximum circuit pressure (1250 PSI) is limited by a re-
lief valve in the gear pump.
When the cutting units are in the raised position, flow
from the gear pump (P3) is by-passed through the steer-
ing control valve, hydraulic manifold, 250 PSI relief
valve, and to the hydraulic reservoir.
Reelmaster 5200-D/5400-D
To lower the cutting units, solenoid valves (S3), (S4),
and (S5) energize along with solenoid valve (S6). Valve
(S6) is a load holding poppet-type valve. Solenoid valve
(S7) is in its normally de-energized position, and allows
oil from the rod end of the cylinders to return to the hy-
draulic reservoir. Hydraulic pressure against the piston
side of the cylinder causes the shafts to extend, and low-
er the cutting units. When the solenoids are deener-
gized, the lift cylinders are locked in the lowered
position.
The 250 PSI relief valve maintains a back pressure on
the lift cylinders as they dump oil to the hydraulic reser-
voir.
Page 4 - 13 Hydraulic System