Toro Groundsmaster 4100-D Service Manual

Also see for 30447: Operator's manual Installation instructions Installation instructions

Contents

Groundsmaster 4100--D/4110--DHydraulic System Page 4 -- 20Mow Circuit Cutting Deck Blade BrakingWhen the operator turns the PTO switch OFF or if a deckis raised with the PTO switch ON, PTO manifold sole-noid valve (S) is de--energized causing bypass cartridge(LC1) to shift (refer to information in Mow Circuit in thissection). This shifted cartridge allows oil return out man-ifold port P2. At the same time, solenoid valve (S) in itsneutral position prevents any sense line flow through thespool which causes the brake cartridge (LC2) to shift toits neutral position blocking return flow from the deckmotor and slowing the cutting blades (Fig. 11).The inertia of the rotating cutting blades, however, effec-tively turns the deck motor into a pump causing an in-crease in pressure as the flow from the motor comes upagainst the closed brake cartridge (LC2). When thispressure builds to approximately 600 PSI (41 bar), reliefvalve (RV2) opens which allows a small amount of hy-draulic flow to return to tank through a manifold sensingline (Fig. 12). This flow causes a pressure increase thatshifts brake cartridge (LC2) to once again allow oil flowfrom the motor (Fig. 13). When return pressure dropsbelow 600 PSI (41 bar), relief valve (RV2) reseats andcauses LC2 to close again blocking return flow from thedeck motor to further slow the cutting blades. This actionof the brake relief valve opening and the brake cartridgeshifting occurs several times in a very short time frameas the blades finally come to a stop. Once the bladeshave stopped, brake cartridge LC2 remains in the neu-tral position to keep the deck motor from rotating.Figure 11PTOMANIFOLDPUMP FLOWRETURNFigure 12PTOMANIFOLDPUMP FLOWRETURNFigure 13PTOMANIFOLDPUMP FLOWRETURN