Service Manual

Groundsmaster 4300--DHydraulic System Page 4 -- 32
Testing
The most effective method for isolating problems in the
hydraulic system is by using hydraulic test equipment
such as pressure gauges and flow meters in the circuits
during various operational checks (see the Special
Tools section in this chapter).
Before Performing Hydraulic Tests
IMPORTANT: All obvious areas such as oil supply,
oil filter, binding linkages, loose fasteners or im-
proper adjustments must be checked before as-
suming that a hydraulic component is the source of
a problem.
Precautions for Hydraulic Testing
CAUTION
Failure to use gauges with expected pressure
(psi/bar) rating as listed in test procedurescould
result in damage to the gauge and possible per-
sonal injury from leaking hot oil.
CAUTION
All t esting should be performed by two (2)
people.One person shouldbe in theseat to oper-
ate the machine and the other should read and
record test results.
WARNING
Keep body and hands away from pin hole leaks
or nozzles that eject hydraulic fluid under high
pressure. Do not use hands to search for leaks;
use paper or cardboard. Hydraulic fluid escap-
ing under pressure can have sufficient force to
penetrate the skin and cause serious injury. If
fluidisinjectedintotheskin,itmustbesurgical-
ly removed within a few hours by a doctor famil-
iar with this type of injury. Gangrene may result
from such an injury.
1. Clean machine thoroughly before disconnecting or
disassembling any hydraulic components. Always keep
in mind the need for cleanliness w hen working on hy-
draulic equipment. Contamination can cause excessive
wear or binding of hydraulic components.
2. Review all test steps before starting the test proce-
dure.
3. Before testing, check all control linkages for improp-
er adjustment, binding or broken parts.
4. All hydraulic tests should bemade with the hydraulic
oil at normal operating temperature.
WARNING
Before disconnecting or performing any work on
the hydraulic system, all pressure in the system
must be relieved. See Relieving Hydraulic Sys-
tem Pressure in the General Information section
of this chapter.
5. Put metal caps or plugs on any hydraulic lines left
open or exposed during testing or component removal.
6. Whenusing hydraulic tester (pressure and flow), the
inlet and the outlet hoses must be properly connected
and not reversed to prevent damage to the hydraulic
tester or components.
7. Install hydraulic fittings finger tight and far enough to
makesurethattheyarenotcross--threadedbeforetight-
ening them with a wrench.
8. Position tester hoses to prevent rotating machine
parts from contacting and damaging the hoses or tester.
9. After connecting test equipment, check oil level in
the hydraulic tank to make sure that oil level is correct.
10.When using hydraulic tester (pressure and flow),
opentesterloadvalvecompletelybeforestartingengine
to minimize the possibility of damaging components.
11.Theenginemustbeingoodoperating condition.Use
a phototac when performing a hydraulic test. Engine
speed can affect the accuracy of the tester readings.
Check actual speed of the pump when performing hy-
draulic flow tests.
12.After hydraulic test procedures have been com-
pleted, check oil level in the hydraulic tank to make sure
that oil level is correct.