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Groundsmaster 4500--D/4700--D Hydraulic SystemPage 4 -- 67
NOTE: Gear Pump P4 supplies oil flow for the engine
cooling fan circuit.
Procedure for Gear Pump P4 Flow Test
1. Make sure hydraulic oil is at normal operating tem-
peraturebyoperatingthemachineforapproximatelyten
(10) minutes. Make sure the hydraulic tank is full.
2. Park machine on a level surface with the cutting
decks lowered and off. Make sure engine is off and the
parking brake is engaged.
3. Raise hood to allow access to pump assembly.
CAUTION
Prevent personal injury and/or damage to equip-
ment. Read all WARNINGS, CAUTIONS and Pre-
cautions for Hydraulic Testing at the beginning
of this section.
4. Thoroughly clean junction of hydraulic hose and fit-
ting in gear pump section P4 (Fig. 55). Disconnect hy-
draulic hose from fitting.
IMPORTANT: Make sure that the oil flow indicator
arrow on the tester is showing that the oil will flow
from the gear pump fitting, through the tester and
into the disconnected hose.
5. Install tester with pressure gauge and flow meter in
series with the disconnected hose and fitting in gear
pump section P4.Make surethe flowcontrol valveon
the tester is fully open.
6. After installing tester, start engine and run at idle
speed. Check for hydraulic leakage and correct before
proceeding with test.
7. Move throttleto full speed (2870RPM). DO NOT en-
gage the cutting decks.
IMPORTANT: The gear pump is a positive displace-
ment type. If pump flow is completely restricted or
stopped, damage to the pump, tester or other com-
ponents could occur.
8. While watching pressure gauge, slowly close flow
control valve on tester until 1000 PSI (69 bar) is ob-
tained on pressure gauge. Verify engine speed contin-
ues to be correct (2870 RPM).
9. For a pump in good condition, flow indication should
be approximately 6.3 GPM (23.8 LPM).
10.Fully open flow control valve on tester and then shut
engine off. Record test results.
11.If the flow is lower than 5.3 GPM (20.1 LPM) or a
pressure of 1000 PSI (69 bar) could not be obtained,
check for restriction in pump intake line. If intake line is
not restricted, remove gear pump and repair or replace
as necessary.
12.Lower and secure hood after testing is completed.
1. Gear pump 2. Pump section P4 hose
Figure 55
2
1
FRONT
RIGHT
Hydraulic
System