Toro Groundsmaster 4300-D Service Manual page 129

Test Procedure (continued)
Groundsmaster ® 4300-D
16226SL Rev C
3. To test the front cutting unit circuit relief valve PRV2, clean and disconnect
the inlet hose to the #4 (front left) cutting deck motor
4. To test the rear cutting unit circuit relief valve PRV1, clean and disconnect
the inlet hose to the #2 (rear left) cutting deck motor
Ensure that the fluid flow indicator arrow on the flow meter is
showing that the fluid will flow from the disconnected hose, through
the tester, and into the deck motor.
5. Install a tester with the pressure gauge and flow meter in series with the
disconnected hose and the deck motor. Ensure that the flow control valve
on tester is fully open.
6. Ensure that the hydraulic fluid is at normal operating temperature by
operating the machine for at least 10 minutes.
7. With the engine running, press the engine speed switch to full speed (3,005
to 3,055 rpm) position. Use the InfoCenter to check that the engine speed is
correct.
Keep away from the cutting deck during the test to prevent personal
injury.
8. Have a second person to occupy the seat, press the PTO switch to O
position, and then move the joystick lever forward to engage the cutting
decks.
Do not hold over relief for longer than necessary to obtain the
pressure reading, while you perform this test.
9. Monitor the pressure gauge carefully while you slowly close the tester
flow control valve. As the relief valve lifts, the pressure gauge needle will
momentarily stop.
Note: The system pressure will continue to increase, once the relief valve is
opened.
10. Once the relief valve lifts, the system pressure should be:
• Approximately 17,500 kPa (2,500 psi) for the relief valve (PRV1)
• Approximately 24,100 kPa (3,500 psi) for the relief valve (PRV2)
11. Open the tester flow control valve, disengage the cutting decks and shut off
the engine.
12. If the pressure is incorrect, remove the PRV valve on the mow manifold, and
clean or replace the valve; refer to the
Assembly (page 4–127).
13. If you are not able to obtain relief pressure, check for a restriction in the pump
intake line and/or check the gear pump (P2) (front cutting deck circuit) and/or
IMPORTANT
WARNING
IMPORTANT
Servicing the Deck Control Manifold
Page 4–67 Hydraulic System: Testing the Hydraulic System
(Figure 66).
(Figure 67).
N