Toro Groundsmaster 4500-D Service Manual page 115

Flush Hydraulic System
IMPORTANT: Flush the hydraulic system any time
there is a severe component failure or the system is
contaminated (oil appears milky, black or contains
metal particles).
IMPORTANT: Flush hydraulic system when chang-
Ing from petroleum base hydraulic fluid to a biode-
gradable fluid. Operate machine under normal
operating conditions for at least four (4) hours be-
fore draining.
1. Park machine on a level surface. Lower cutting
decks, stop engine and engage parking brake. Remove
key from the ignition switch.
WARNING
Before disconnecting or performing any work
on the hydraulic system, all pressure in the sys-
tem must be relieved. See Relieving Hydraulic
System Pressure in the General Information sec-
tion in this chapter.
IMPORTANT: Make sure to clean around all hydrau-
lic connections that will be disconnected for drain-
ing.
2. Drain hydraulic reservoir into a suitable container.
3. Drain hydraulic system. Drain all hydraulic hoses,
tubes and components while the system is warm.
4. Remove and replace both hydraulic oil filters.
5. Inspect and clean hydraulic reservoir (see Hydraulic
Reservoir in this section).
IMPORTANT: Follow all local codes and regulations
when recycling or disposing hydraulic fluid and fil-
ters.
Groundsmaster 4500--D/4700--D
6. Connect all hydraulic hoses, tubes and components
that were disconnected while draining system.
NOTE: Use only hydraulic fluids specified in the Trac-
tion Unit Operator's Manual. Other fluids may cause
system damage.
7. Fill hydraulic reservoir with new hydraulic fluid.
8. Prime hydraulic pumps (see Priming Hydraulic
Pumps in this section).
9. Start engine and let it run at low idle speed for a mini-
mum of two (2) minutes. Increase engine speed to high
idle for minimum of one (1) minute under no load.
10.Raise and lower cutting decks several times. Turn
steering wheel fully left and right several times.
11. With cutting decks fully lowered and the operator
seat occupied, engage cutting decks and let them run
for several minutes. Move PTO switch to OFF.
12.Shut off engine and check for hydraulic oil leaks.
Check oil level in hydraulic reservoir and add correct
amount of oil if necessary.
13.Operate machine for two (2) hours under normal op-
erating conditions.
14.Check condition of hydraulic oil. If the new fluid
shows any signs of contamination, repeat steps 1
through 13 again until oil is clean. If changing to biode-
gradable fluid, repeat steps 1 through 13 again at least
once and until the oil is clean.
15.Assume normal operation and follow recommended
maintenance intervals.
Page 4 - - 75 Hydraulic System