Mow And Backlap - Toro 04384 Service Manual

Mow and Backlap

The tandem gear pump is directly coupled to the piston
(traction) pump. The front gear pump section supplies
oil flow to the hydraulic manifold block and to the cutting
reel motors. The gear pump takes its suction directly
from the hydraulic reservoir. Maximum circuit pressure
is limited by solenoid relief valve (S1R1) which is located
in the hydraulic manifold.
With the engine running and the Functional Control and
Raise/Lower/Mow levers positioned so the reels will
not turn, solenoid relief valve (S1R1) in the hydraulic
manifold is de--energized. The de--energized (S1R1)
by--passes flow from the front section of the gear pump
to the oil filter and hydraulic reservoir. Additionally, man-
ifold pressure reducing valve (PRV) will remain seated
to prevent the reel motors (and reels) from rotating.
Mow
With the engine running and the Functional Control and
Raise/Lower/Mow levers positioned so the reels will
turn, solenoid relief valve (S1R1) is energized. In the en-
ergized position, this valve directs oil flow to the reel mo-
tors and also functions as the mow circuit relief valve.
Greensmaster 3250--D
Oil flow from manifold port (P1) flows through the reel
speed control valve (FC). Flow across the speed control
valve is pressure compensated by the logic cartridge
valve (LC). The logic cartridge valve maintains a pres-
sure differential of 75 PSI (5.2 bar) across the speed
control valve. Any excess flow above the speed control
valve setting is by--passed to the reservoir through the
logic cartridge valve. With the backlap valve (MR) in the
mow position, oil flows through the backlap valve, out
manifold port (MA) and to the reel motors that are con-
nected in series. Oil flows through the left, right and then
center reel motor as it turns the motors in the mow direc-
tion.
When in the mow position, mow circuit pressure will
cause the hydraulic manifold pilot piston to shift and
open the pressure reducing valve (PRV). The shifted
pressure reducing valve allows circuit oil to return to the
reservoir through the manifold block and oil filter.
Backlap
Backlapping operation is the same as mowing opera-
tion, except for the position of the backlap valve (MR).
When the backlap valve (MR) is in the backlap position,
oil flows through the center, right and then left reel motor
as it turns the motors in the backlap direction.
Page 4 - - 17 Hydraulic System