Textron Jacobsen SLF530, Repair Manual

Page: 223 / 352

HYDRAULICS
673831-Rev A 6-29
6
10. Bypass seat switch.
NOTE
Verify engine rpm is within specification (3000 rpm ± 50)
to ensure accurate hydraulic test results.
11. Start engine and run at full throttle (3000 rpm ± 50).
12. Use the flow meter to warm the hydraulic oil. Turn the
flow meter valve (6) until a reading of 1100 psi
(75 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.
13. Engage the mow switch, engage and release the
lift/lower joystick to the lower position twice, and
operate the reels.
14. Read and record the front cutting units circuit no load
flow.
15. Slowly close flow meter valve (6) until a pressure of
1650 psi (114 bar) or 75% of the relief valve rating is
reached. Read and record the front cutting units
circuit loaded flow.
16. Open flow meter valve (6), disengage mow switch,
and stop engine.
17. Calculate front cutting units circuit leakage.
(Step 14 – Step 15 / Step 14 x 100 = Leak
Percentage)
Is front cutting units circuit leakage 10% or less?
YES The front cutting units circuit is good.
Proceed to “Front Reel Motors Test” on
page 6-32.
NO Proceed to next question.
Is front cutting units circuit leakage 11% to 20%?
YES The front cutting units circuit is marginal.
Additional testing is required. Proceed to
“Front Cutting Units Pump Test” on
page 6-29.
NO Proceed to next question.
Is front cutting units circuit leakage 21% or
more?
YES Test individual components in front cutting
units circuit for leakage. Proceed to “Front
Cutting Units Pump Test” on page 6-29.
Front Cutting Units Pump Test
See Figures 6-19 through 6-21.
IMPORTANT
• Performing this test will isolate the front cutting
units pump from the rest of the front cutting units
circuit.
• This test works together with the “Front Cutting
Units Circuit Test,” “Front Reel Valve Test,” and
“Front Reel Motors Test” to isolate a problem
with the front cutting units circuit.

WARNING
1. Park the mower safely. (See “Park Mower Safely” on
page 1-6.)
2. Before performing this test, perform “Front Cutting
Units Circuit Test,” leaving flow meter connected as
outlined.
Figure 6-19
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
• -6 ORFS Test Hose 4000 psi (276 bar)
• -6 ORFS Tee Fitting
• -6 ORFS Blocking Disk
4
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MAR0160