HYDRAULICS
4203781 First Edition 6-31
6
!
CAUTION
9. Slowly close flow meter valve (2) until pressure
reaches 2250 psi (155 bar). Read and record the
front cutting unit pump loaded flow.
10. Open flow meter valve (2), disengage switches, and
stop engine.
11. Calculate front cutting unit pump leakage.
(Step 12 of previous test – Step 9 / Step 12 of
previous test x 100 = Leak Percentage)
Is front cutting unit pump leakage 10% or less?
YES The front cutting unit pump is good. Proceed
to “Front Cutting Unit Deck Valve Test” on
page 6-31.
NO Proceed to next question.
Is front cutting unit pump leakage 11% to 20%?
YES The front cutting unit pump is marginal.
Additional testing is required. Proceed to
“Front Cutting Unit Deck Valve Test” on
page 6-31.
NO Proceed to next question.
Is front cutting unit pump leakage 21% or more?
YES Repair or replace front cutting unit pump.
(See “Gear Pump” on page 6-58.) Then
proceed to “Front Cutting Unit Deck Valve
Test” on page 6-31.
Front Cutting Unit Deck Valve Test
See Figures 6-22 through 6-24.
!
WARNING
1. Park the mower safely. (See “Park Mower Safely” on
page 1-6.)
2. Before performing this test, perform front cutting unit
circuit test, leaving flow meter connected as outlined.
Figure 6-22
3. Install blocking disk at fitting (1) on left front cutting
unit motor, blocking oil flow from entering left front
cutting unit motor.
Figure 6-23
4. Open flow meter valve (2) completely.
5. Bypass seat switch and set park brake.
Do not exceed 3350 psi (231 bar) when testing
pump or equipment damage may occur.
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
• -10 ORFS Test Hose 3600 psi (248 bar)
• -10 ORFS Tee Fitting
• -10 ORFS Blocking Disk
TN2132
1
TN1363
2