Textron Jacobsen SLF530, Repair Manual

Page: 155 / 352

HYDROSTATIC POWER TRAIN
673831-Rev A 5-29
5
15. Use the flow meter to warm the hydraulic oil. Turn the
flow meter valve (10) until a reading of 2030 psi (140
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.
16. If 4WD option is installed, activate 4WD on the LDU
and place a piece of metal in sensing area of forward
switch under the traction pedal.
17. After warming the hydraulic oil, verify flow lock tool is
adjusted to allow pump to produce 15 gpm (57 lpm)
in the forward direction.
1 8 . Read and record no load flow.
19. Slowly close flow meter valve (7) until pressure
reaches 3045 psi (210 bar). Read and record loaded
flow.
20. Open flow meter valve (10), stop engine, and set
parking brake. Return flow lock tool back to neutral
position.
21. Calculate traction system leakage.
(Step 1 8 – Step 19 / Step 1 8 x 100 = Leakage
Percentage)
Is traction system leakage 10% or less?
YES The traction system is good. Continue to
step 22.
NO Proceed to next question.
Is traction system leakage 11% to 20%?
YES The traction system is marginal. Continue to
Traction Pump Tests.
NO Proceed to next question.
Is traction system leakage 21% or more?
YES The traction system is faulty. Continue to
Traction Pump Tests.
22. Disconnect and remove test equipment. Install all
hoses and fittings as noted prior to removal.
23. Install and connect all components as noted prior to
test.
24. Check hydraulic oil level. Add oil as needed. (Refer to
“Safety, Operation, and Maintenance Manual” for oil
specifications.)
Traction Pump Tests
See Figure 5-24.

WARNING
1. Park the mower safely. (See “Park Mower Safely” on
page 1-6.)
2. Before performing this test, perform traction system
test leaving flow meter, flow lock tool, and wheel
restraints connected/installed as outlined. (See
“Traction System Test” on page 5-2
8 .)
Figure 5-24
3. Install blocking disks at locations (11 and 12).
4. Open flow meter valve (10) completely before
starting engine.
5. Put the parking brake switch in the ON position.
6. Bypass the seat switch.
NOTE
Verify engine rpm is within specification (3000 rpm ± 50)
to ensure accurate hydraulic test results.
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
• -12 ORFS Test Hose 6000 psi (413 bar)
• -12 ORFS Blocking Disks
• Flow Lock Tool
15
GPM
20
25
30
10
5
0
0
20
40 60
LPM
80
100
3000
psi
BAR
0
1
00
200
3
0 0
40
0
3600
420
0
48
0
0
54
0
0
60
00
24
00
18
00
1
200
6
0
0
0
250
psi
BAR
0
5
1
0
15 20
25
3
0
35
300
350
4
00
4
5
0
50
0
20 0
150
1
00
5
0
0
12
11
2
4
6
8
10
MAR00 88