Service Manual

Rev. A

Groundsmaster 4500- D/4700- D Hydraulic SystemPage 4 - 21

Raise Cutting Decks: Groundsmaster 4500- D

A four section gear pump is coupled to the piston (trac-

tion) pump. The third gear pump section supplies hy-

draulic flow to both the lift control manifold and the

steering control valve. Hydraulic flow from this pump

section is delivered to the c ircuits through a proportional

flow divider located in the fan control manifold. Maxi-

mum lift/lower circuit pressure is limited to 1600 PSI (110

bar) by a relief valve (RV) in the lift control manifold. L ift

circuit pressure can be monitored at test fitting G1 on the

lift control manifold.

On the Groundsmaster 4500- D, a single lift switch on

the console arm is used to raise and lower the five (5)

cutting decks (Fig. 14).

When the cutting decks are in a stationary position (not

raising or lowering), lift circuit flow from the third gear

pump section bypasses the lift cylinders through the lift

control manifold solenoid valve S5 and proportional re-

lief valve TS which are de- energized. Return flow from

the manifold is routed to the oil filter and traction charge

circuit.

NOTE: The operator must be in the operator seat in or-

der to raise the cutting decks.

Cutting Deck Raise

To raise the five (5) cutting decks on a Groundsmaster

4500- D, the rear of the lift switch is depressed. The

switch acts as an input to the TEC- 5002 controller which

then provides an electrical output to solenoid valve S5

in the lift control manifold. Energized solenoid valve S5

shifts to allow a passage for oil flow to the rod ends of the

five (5) deck lift cylinders. The oil flow causes the lift cyl-

inders to retract and raise all of the cutting decks. The

junction manifold orifice leading to the #1 deck is by-

passed during deck raising.

Figure 14

1. Console arm 2. Lift switch

Figure 15

GM- 4500 CUTTING DECK LOCATIONS

#4 #1 #5

#3#2

Hydraulic

System