Jacobsen AR3, Technical/Repair Manual

Page: 161 / 342

5-14 4181384 First Edition
HYDROSTATIC POWER TRAIN
5
17. Start engine and run at full throttle (3150 rpm ± 50).
18. Adjust flow lock tool (1) to allow pump to produce 10
gpm (37.8 lpm) in the forward direction.
19. Use the flow meter to warm the hydraulic oil. Turn the
flow meter valve (10) until a reading of 1525 psi (105
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.
20. After warming the hydraulic oil, verify flow lock tool is
adjusted to allow pump to produce 10 gpm (37.8 lpm)
in the forward direction.
21. Read and record no load flow.
22. Slowly close flow meter valve (10) until pressure
reaches 2300 psi (159 bar). Read and record loaded
flow.
23. Stop engine and return flow lock tool back to neutral
position.
24. Calculate traction system leakage.
(Step 21 – Step 22 / Step 21 x 100 = Leakage
Percentage)
Is traction system leakage 10% or less?
YES The traction system is good. Proceed to step
25.
NO Proceed to next question.
Is traction system leakage 11% to 20%?
YES The traction system is marginal. Additional
testing is required.
NO Proceed to next question.
Is traction system leakage 21% or more?
YES Test individual components in traction
system for leakage.
25. Disconnect and remove test equipment. Install all
hoses and fittings as noted prior to removal.
26. Check hydraulic oil level. Add oil as needed. (Refer to
“Safety, Operation, and Maintenance Manual” for oil
specifications.)
Traction Pump Tests
See Figures 5-13 and 5-14.
!
WARNING
1. Park the mower safely. (See “Park Mower Safely” on
page 1-7.)
2. Before performing this test, perform traction system
test leaving flow meter and flow lock tool connected
as outlined. (See “Traction System Test” on
page 5-12.)
Figure 5-13
3. Install blocking disks at locations (1) and (3).
4. Open flow meter valve (2) completely before starting
engine.
NOTE
Verify engine rpm is within specification (3150 rpm ± 50)
to ensure accurate hydraulic test results.
5. Start engine and run at full throttle (3150 rpm ± 50).
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 4000 psi (276 bar)
• Blocking Disks
• Flow Lock Tool
5
TN1357
4
2
1
3