Toro Groundmaster 31900, Service Manual

Page: 101 / 355

Reverse Direction
The traction circuit operates essentially the same in reverse as it does in the
forward direction. However, the flow through the circuit is reversed. Pushing
the bottom of the traction pedal rotates the piston (traction) pump swash plate
to create a flow of oil. This oil is directed through the hydraulic manifold and on
to the front wheel motors to drive the wheels in the reverse direction. Reverse
traction pressure is limited to 25,000 kPa (3625 psi) by the reverse traction relief
valve (R2) located in the piston (traction) pump.
For 4WD machines, check valves in the hydraulic manifold allow the hydraulic
fluid to bypass the rear wheel motors. The rear wheels do not provide traction in
reverse.
Hydraulic fluid flowing from the wheel motors returns to the piston (traction)
pump and is continuously pumped through the closed loop traction circuit as long
as the traction pedal is pushed rearward.
The charge circuit and flushing valve function the same in reverse as they do in
the forward direction.
Groundsmaster ® 3200, 3300 and 3310 Page 5–15 Hydraulic System: Hydraulic Flow Diagrams
19240SL Rev A