Jacobsen AR3, Техническое руководство по ремонту

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6-42 4181384 First Edition
HYDRAULICS
6
11. Calculate lift/steer pump leakage.
(Step 6 – Step 7 / Step 6 x 100 = Leak Percentage)
Is lift/steer pump leakage 10% or less?
YES The lift/steer pump is good. Proceed to step
10.
NO Proceed to next question.
Is lift/steer pump leakage 11% to 20%?
YES The lift/steer pump is marginal. Additional
testing is required.
NO Proceed to next question.
Is lift/steer pump leakage 21% or more?
YES Repair or replace lift/steer pump. (See
“Tandem Pump” on page 6-44.)
12.
Disconnect and remove test equipment. Install all
hoses and fittings as noted prior to removal.
13. Check hydraulic oil level. Add oil as needed. (Refer to
“Safety, Operation, and Maintenance Manual” for
correct oil specifications.)
Lift Valve Leakage Test
See Figures 6-36 and 6-37.
!
WARNING
1. Park the mower safely. (See “Park Mower Safely” on
page 1-7.)
2. Before performing this test perform lift system test.
Leave flow meter connected as outlined in lift system
test, but remove blocking disk and reconnect hose to
tee fitting.
3. Bypass seat switch and raise seat platform.
Figure 6-36
4. Install blocking disk at fitting (1) on lift valve,
preventing oil flow from entering lift cylinders.
Figure 6-37
5. Open flow meter valve (2) completely.
Verify engine rpm is within specification (3150 rpm ± 50)
to ensure accurate hydraulic test results.
6. Start engine and run at full throttle (3150 rpm ± 50).
7. Use the flow meter to warm the hydraulic oil. Turn the
flow meter valve (2) until a reading of 800 psi (55 bar)
or one half of the relief valve rating is reached. Warm
oil to 120—150°F (49—65°C), open valve fully after
operating temperature is reached.
8. Hold the lever in the raise position.
9. Slowly close flow meter valve (2) until pressure
reaches 1200 psi (83 bar). Read and record the
lift/steer pump loaded flow.
10. Open flow meter valve (2) and stop engine.
The hydraulic system is under pressure, and the
oil will be hot.
• Always relieve pressure in the hydraulic
system before performing service.
• Failure to follow appropriate safety
precautions may result in death or serious
injury.
Required Tools and Materials
• Flow Meter
• Test Hose 2000 psi (138 bar)
• Tee Fitting
• Blocking Disk
TN1302
1
TN1363
2