Jacobsen AR3, Technical/Repair Manual

Page: 232 / 342

HYDRAULICS
4181384 First Edition 6-41
6
!
CAUTION
10. Use the flow meter to warm the hydraulic oil. Turn the
flow meter valve (4) 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.
11. Hold the lever in the raise position.
12. Read and record the lift/steer pump no load flow.
13. While holding the raise/lower switch in the raise
position, slowly close flow meter valve (4) until
pressure reaches 1200 psi (83 bar).
14. Hold the lever in the raise position.
15. Read and record the lift/steer pump loaded flow.
16. Open flow meter valve (4) and stop engine.
17. Calculate lift system leakage. (Step 12 – Step 15 /
Step 12 x 100 = Leak Percentage)
Is lift system leakage 10% or less?
YES The lift system is good. Proceed to step 18.
NO Proceed to next question.
Is lift system leakage 11% to 20%?
YES The lift system is marginal. Additional testing
is required.
NO Proceed to next question.
Is lift system leakage 21% or more?
YES Test individual components in lift system for
leakage.
18.
Disconnect and remove test equipment. Install all
hoses and fittings as noted prior to removal.
19. Check hydraulic oil level. Add oil as needed. (Refer to
“Safety, Operation, and Maintenance Manual” for
correct oil specifications.)
Lift/Steer Pump Test
See Figures 6-34 and 6-35.
!
WARNING
1. Park the mower safely. (See “Park Mower Safely” on
page 1-7.)
2. Raise seat platform.
3. Bypass seat switch.
4. Before performing this test perform lift system test.
Leave flow meter connected as outlined in lift system
test. Install blocking disk between hose (2) and tee
fitting (5). (See “Lift System Test” on page 6-40.)
5. Open flow meter valve (4) completely. (See
Figure 6-35.)
NOTE
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 (4) 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).
8. Open flow meter valve (4) completely. Read and
record the lift/steer pump no load flow.
!
CAUTION
9. Slowly close flow meter valve (4) until pressure
reaches 1200 psi (83 bar). Read and record the
lift/steer pump loaded flow.
10. Open flow meter valve (4) and stop engine.
Do not exceed 1200 psi (83 bar) as this test does
not utilize system relief.
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
Do not exceed 1200 psi (83 bar) as this test does
not utilize system relief.