Jacobsen HR 5111, Service And Repair Instructions

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GENERAL
The purpose of this section is to provide a guide for
field testing the hydraulic system. More extensive test
procedures, using test instruments, are presented in
Section 8R. Component location illustrations, hydrau-
lic schematics and diagrams are presented in Section
8S. Before performing any tests see “Preliminary Checks”
below.
AS A SAFETY REMINDER
•
Follow the procedures one step at a time.
•
Observe all NOTES, CAUTIONS and WARNINGS.
•
Pay attention to what you are doing. Work with a
safety conscious attitude.
•
Use care working with HOT oil.
•
Wear safety glasses at all times.
•
Keep hands and feet away from the moving parts.
•
Engine must be shut off and attachments lowered to
ground when making adjustments or hydraulic connec-
tions unless otherwise specified in the test instructions.
PRELIMINARY CHECKS
The following preliminary checks should be made be-
fore performing any tests.
1. The reservoir should be checked for proper level,
the presence of water (noted by a cloudy or milky
appearance), air (noted by a foaming appearance),
or a rancid odor indicating excessive heat.
If any of the above symptoms appear, or if the hy-
draulic oil becomes contaminated, or after a major
component failure, the oil should be changed and
system flushed.
NOTE
Use only the recommended hydraulic oil (see Sec-
tion 11 — Preventive Maintenance). Always change
the filter when changing the oil.
The filter should be changed after the initial
25 hours of operation. Thereafter, the filter
should be changed approximately every 250
hours.
2. Check all lines and fittings for leakage and tighten
as necessary (see Section 8C).
3. To eliminate all possible mechanical problems first,
complete the steps presented in block form below
before starting the hydraulic tests.
FIELD TESTS
When a hydraulic failure occurs, some simple, effec-
tive tests can be performed prior to using a test instru-
ment. The results of these tests can lead you to the
suspected component failure. If further testing is nec-
essary, proceed to INSTRUMENT TESTS.
CHARGE PUMP
The charge pump (section #4 implement pump) sup-
plies oil for the power steering unit, lift and lower, dif-
ferential lock, 4 wheel drive valve and for charging the
hydrostat for traction.
If a fault affects all the systems, proceed with an in-
strument test for the charge pump.
TRACTION PUMP (See Figure 8Q-2)
NOTE
Before performing any tests, be sure dump valve
located on top of the traction pump is closed (see
Figure 8Q-1).
1. Remove left hydraulic lines from traction pump.
Cap line and plug motor port.
2. Be sure the oil is at operating temperature.
3. With the engine throttle wide open, slowly step on
the “forward” traction pedal.
•
If the engine stalls or labors the pump is okay.
A fault may exist in the main traction motor or 4
wheel drive assembly.
HYDRAULICS
SECTION 8Q. HYDRAULIC FIELD TEST PROCEDURES
8Q-1
8Q
Figure 8Q-1. Dump Valve