Jacobsen SLF 1880, Техническое руководство по ремонту

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8M-89
SECTION 8M. HYDRAULIC FIELD TEST PROCEDURES
GENERAL
When a hydraulic failure occurs, some simple, effective
tests can be performed prior to using a test instrument.
The results of these tests can lead you to the sus-
pected component failure. More extensive test proce-
dures, using test instruments, are presented in
(Section 8N). Component location illustrations are pre-
sented in (Section 8U). Hydraulic schematics and The-
ory of operation are presented in (Section 8D) and
(Section 8L). Before performing any tests please
review “As A Safety Reminder” and “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 when working with HOT oil.
• Wear safety glasses at all times.
• Keep hands and feet away from the mower blades.
• The engine must be shut off and the attachments
lowered to the grounded when making adjustments
or hydraulic connections unless otherwise specified
in the test instructions.
PRELIMINARY CHECKS
The following checks should be made before perform-
ing any tests.
1. The reservoir should be checked for proper level,
the presence of water (noted by cloudy or milky
appearance), air (noted by a foaming appear-
ance), or a rancid odor indicating excessive heat.
• If any of the above symptoms appear, or if the
hydraulic oil becomes contaminated, or after a major
component failure, the system should be flushed,
the oil changed, and a new filter installed.
2. Check all lines and fittings for leakage and tighten
as necessary (Section 8C).
3. Eliminate all possible mechanical problems before
starting the hydraulic tests.
LIFT SYSTEM TEST
The purpose of this test is to determine if the lift cylin-
ders are bypassing fluid internally (Figure 8M-1).
1. Operate the mower until the hydraulic oil reaches
operating temperature, 110 – 130
°
F (43 – 54
°
C).
2. Lift the reels and shut off the engine.
3. Measure the distance between the bottom of a
reel and the ground.
4. Allow the mower to stand for 15 minutes.
Conclusion
• If the reels do not drop, the lift system has no
internal leakage.
• If any of the reels show signs of dropping, proceed
with the test.
5. Start engine raise reels and shut off engine.
6. Lift and support the reel with a floor jack with
board between the jack and reel to protect the
reel.
7. Disconnect the hydraulic hose from the extend
side (Barrel End) of the lift cylinder. Immediately
plug the hydraulic hose (Figure 8M-1).
8. Install a separate test hose onto lift cylinder fitting.
9. Place a container underneath the cylinder (mini-
mum 1-gallon (3.8-liter)) capacity and place the
separate test hose into container.
NOTICE
Use only the recommended hydraulic oil
(Section 11). Always change the filter when chang-
ing the oil. The filter should be changed after the ini-
tial 50 hours of operation. Thereafter, the filter
should be changed approximately every 500 hours.
8M