HYDRAULICS
4181383 First Edition 6-39
6
Lift/Steer Pump Test
!
WARNING
1. Park the mower safely. (See “Park Mower Safely” on
page 1-5.)
2. 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 6-37.)
3. Open flow meter valve (4) completely. (See
Figure 6-33.)
4. Bypass seat switch.
NOTE
Verify engine rpm is within specification (2850 rpm ± 50)
to ensure accurate hydraulic test results.
5. Start engine and run at full throttle (2850 rpm ± 50).
!
CAUTION
6. Use the flow meter to warm the hydraulic oil. Turn the
flow meter valve (4) until a reading of 900 psi (62 bar)
or one half of the relief valve rating is reached. Warm
oil to 120—150°F (49—65°C).
7. Open flow meter valve (4) completely. Read and
record the lift/steer pump no load flow.
8. Slowly close flow meter valve (4) until pressure
reaches 1300 psi (90 bar). Read and record the
lift/steer pump loaded flow.
9. Open flow meter valve (4) and stop engine.
10. Calculate lift/steer pump leakage.
(Step 7 – Step 8 / Step 7 x 100 = Leak Percentage)
Is lift/steer pump leakage 10% or less?
YES The lift/steer pump is good. Proceed to
step 11.
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 “Gear
Pump” on page 6-41.)
11. Disconnect and remove test equipment. Install all
hoses and fittings as noted prior to removal.
12. Install and connect all components as noted prior to
test.
13. Check hydraulic oil level. Add oil as needed. (Refer to
“Safety, Operation, and Maintenance Manual” for
correct oil specifications.)
Lift Valve Test
See Figures 6-34 and 6-35.
!
WARNING
1. Park the mower safely. (See “Park Mower Safely” on
page 1-5.)
2. Before performing this test, perform lift system test.
Leave flow meter connected as outlined in lift system
test. (See “Lift System Test” on page 6-37.)
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
• -8 ORFS Test Hose 2000 psi (138 bar)
• -8 ORFS Tee Fitting
• -8 ORFS Blocking Disk
Do not exceed 1800 psi (124 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
• -8 ORFS Test Hose 2000 psi (138 bar)
• -8 ORFS Tee Fitting
• -6 ORFS Blocking Disk
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