Service Manual

Groundsmaster 4300--D Hydraulic SystemPage 4 -- 49
CAUTION
Before opening hydraulic system, operate all hy-
draulic controls to relieve system pressure and
avoid injury from pressurized hydraulic oil. See
Relieving Hydraulic System Pressure in the Gen-
eral Information section of this chapter.
NOTE: The deck motors are connected in series. To
isolate a faulty motor, all motors in the circuit may have
to be tested by starting with the upstream motor first.
5. For deck motor to be tested, thoroughly clean junc-
tion of the motor case drain hose (small diameter hose)
where it connects to traction unit bulkhead (not at the
motor)(Fig.50).Disconnectthe case drain hose andput
a steel cap o n the fitting at the traction unit. Leave the
case drain hose from the motor open and place open
end of disconnected hose into a drain pan.
IMPORTANT: Make sure that the oil flow indicator
arrow on the flow gauge is showing that the oil will
flow from the deck motor, through the tester and
into the return hose.
6. On deck motor to be tested, thoroughly clean junc-
tion of hydraulic return hose and deck motor fitting (Fig.
50).Disconnectreturnhosefromthemotor.Installtester
with pressure gauges and flow meter in series with the
motor and disconnected return hose. Make sure the
flow control valve on tester is fully open.
NOTE: Use a graduated container, special tool
TOR4077, to measure case drain leakage (Fig. 49).
7. Startengine and run at idle speed. Check for any hy-
draulic leakage from test connections and correct be-
fore proceeding with test.
CAUTION
Cutting deck blades will rotate when performing
themotorefficiencytest.Keepawayfromcutting
decks during test to prevent personal injuryfrom
rotating blades. Do not stand in front of the ma-
chine.
8. Sit on seat and move throttle to full speed (3200
RPM). Press PTOswitch to ON. Move joystick lever for-
ward to engage cutting decks.
9. While watching pressure gauges, slowly close flow
control valve on tester until a pressure of 1200 PSI (83
bar) is obtained.
10.After achieving 1200 PSI (83 bar), place discon-
nected motor case drain hose into a container gra-
duatedin ounces or milliliters (e.g.Toro#TOR4077)and
collect hydraulic fluid for 15 seconds. After 15 sec-
onds, remove hose end from container. Then move the
PTO switch to OFF, open the tester flow control valve
and stop the engine.
11.Identify amount of oil collected in the container. Re-
cord test results.
If flow was greater than 22.4 ounces (662 millili-
ters) (0.7 GPM/2.6 LPM), repair or replace the
tested deck motor (see Cutting Deck Motor Service
in the Service and Repairs section of this chapter).
If flow is less than 22.4 ounces (662 milliliters) (0.7
GPM/2.6 LPM), the tested motor does not have ex-
cessive leakage.
12.After testing is completed, make sure that engine is
stopped, then relieve hydraulic system pressure (see
Relieving Hydraulic System Pressure in the General In-
formation section of this chapter). Disconnect tester
from motor and return hose. Connect return hose to the
deck motor. Remove plug from machine bulkheadfitting
and connect case drain hose to the fitting.
13.If necessary, perform motor efficiency test on other
deck motors.
1. Case drain hose
2. Bulkhead fitting
3. Return hose
Figure 50
1
2
3
Hydraulic
System