Toro Greensmaster 3200 Service Manual

Also see for 3200: Operator's manual Operator's manual Operator's manual Operator's manual Installation instructions

Raise and Lower Cutting UnitsRaiseThe gear pump (P2) is directly coupled to the hydrostatthrough gear pump (P1). It supplies hydraulic pressurefor raising and lowering cutting units and maintaining100 to 150 PSI (6.9 to 10.0 bar) to the low pressure sideof the traction circuit (charge pressure). The pump takesits suction from the hydraulic reservoir.During conditions of not lifting or lowering cutting units,flow from the gear pump is by–passed through the steer-ing control valve and solenoid valve (S2) directly to thehydrostat and the charge relief valve(R4). Flow then re-turns to the hydraulic reservoir.When the cutting units are to be raised, solenoid valve(S2) is energized and blocks flow directly to the hydros-tat. Flow is directed to energized solenoid valve (S3),which directs flow to de–energized solenoid valve (S4)and the lift cylinders. Hydraulic pressure against the cyl-inder pistons moves their shafts causing the cuttingunits to raise. At the same time, the pistons push the hy-draulic fluid out of the lift cylinders and back through so-lenoid valves (S4 and S3) to the hydrostat. When thesolenoid valves de–energize, spring action returns thevalves to their original position and by–passes flow backto the hydrostat stopping lift cylinder movement. Thecylinder position is locked in place since there is no com-plete circuit of flow to and from the lift cylinders.LowerCircuit operation for lowering the lift cylinders is similarto raising them. However, the solenoid valve (S3) re-mains de–energized and in the down position and sole-noid valve (S4) is energized and shifts down. Flow isreversed to and from the lift cylinders, thus moving thecutting units down.When the cutting units are to be lowered, solenoid valve(S2) is energized and blocks flow directly to the hydros-tat. Flow is directed to de–energized solenoid valve(S3), which directs flow to energized solenoid valve (S4)and the lift cylinders. Hydraulic pressure against the cyl-inder pistons moves their shafts causing the cuttingunits to lower. At the same time, the pistons push the hy-draulic fluid out of the lift cylinders and back through so-lenoid valves (S4 and S3) to the hydrostat. Flow into theflow control valve is slowed by the variable orifice to al-low the rear cutting unit to lower after the front units.When the solenoid valves de–energize, spring actionreturns the valves to their original position and by–passes flow back to the hydrostat stopping lift cylindermovement.Hydraulic System Page 5 – 10 Greensmaster 3200/3200–D