Toro 4100-D service manual Mow Circuit

Mow Circuit

Hydraulic flow for the mow circuit is supplied by two sec- tions of the gear pump. The gear pump section closest to the piston (traction) pump supplies hydraulic flow to the wing decks, while the next gear pump section sup- plies the center deck.

Each cutting deck is controlled by a hydraulic manifold equipped with a solenoid control valve (S), bypass car- tridge (LC1), brake cartridge (LC2) and relief cartridge (RV1). When the the deck solenoid valve (S) is not ener- gized (PTO switch OFF), hydraulic flow by--passes the deck motor through the bypass cartridge (LC1). When the PTO switch is turned ON, the solenoid valve (S) en- ergizes, causing a shift of the by--pass cartridge (LC1) and allowing hydraulic flow to the deck motor. Brake car- tridge (LC2) and relief cartridge (RV2) control the stop- ping rate of the blade when the solenoid control valve is de--energized as the PTO switch is turned OFF.

The solenoid valve (S) for each wing deck is de--ener- gized any time the wing deck is raised.

Return oil from the deck motors is directed to the oil cool- er and oil filter. Deck motor case drain leakage returns to the hydraulic reservoir.

Maximum mow circuit pressure is limited at each deck by a relief valve (RV1) in the hydraulic manifold. The front and left deck relief valves are set at 3000 PSI (207 bar) and the right deck relief valve is set at 2000 PSI (137 bar).

Circuit pressure can be measured at port (G) of the hy- draulic manifold for each cutting deck.

System

Hydraulic

Groundsmaster 4100--D Page 4 -- 19 Hydraulic System