Service Manual

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.)
j
Failure to use gauges with the recommended
pressure (psi) rating as listed in the test pro-
cedures could result in damage to the gauge
and possible personal in ury from leaking
hot oil.
CAUTION
Before Performing Hydraulic Tests
All obvious areas such as oil supply, filter, binding
linkage, loose fasteners, or improper adjustments must
be checked before assuming that a hydraulic com-
ponent is the source of the problem being experienced.
Do electrical diagnostics before performaing hydraulic
t
ests to make sure the electrical system is operating
properly. If the electrical system is not operating properly
the hydraulic system may appear to malfunction.
j
a
Before disconnecting or performing any work
on the hydraulic system, all pressure in the
system must be relieved by lowering the cut-
ting unit to the ground and shutting the en-
gine OFF.
Keep body and hands away from pin hole
leaks or nozzles that eject hydraulic fluid
under high pressure. Use paper or cardboard,
not hands, to search for leaks. Hydraulic fluid
escaping under pressure can have sufficient
force to penetrate skin and do serious
damage. If fluid is in ected into the skin, it
must be surgically removed within few
hours by a doctor familiar with this type of
injury or gangrene may result.
WARNING
1. Thoroughly clean the machine before disconnecting
or disassembling any hydraulic components. Always
keep in mind the need for cleanliness when working on
hydraulic equipment.
2. Put caps or plugs on any hydraulic lines left open or
ex
posed during testing or removal of components.
3. The engine must be in good operating condition. Use
a tachometer when making a hydraulic test. Engine
speed can affect the accuracy of the tester readings.
4. To prevent damage to tester or components, the inlet
and t
he outlet hoses must be properly connected, and
not reversed (tester with pressure and flow capabilities).
5. To minimize the possibility of damaging components,
co mpletely open th e load v alve by tu rning it
counterclockwise (tester with pressure and flow
capabilities).
6. Install fittings finger tight, far enough to insure that
t
hey are not cross-threaded, before tightening with a
wrench.
7. Position the tester hoses so that rotating machine
par
ts will not make contact with them and result in hose
or tester damage.
8. Check the oil level in the reservoir.
9. Check the control linkage for improper adjustment,
bindi
ng or broken parts.
10. All hydraulic tests should be made with the hydraulic
oil at normal operating temperature.
Testing Page 5 - 18 Groundsmaster
®
300 Series