Toro Groundsmaster 4300-D Service Manual page 139

Test Procedure (continued)
Groundsmaster ® 4300-D
16226SL Rev C
11. Verify the pump flow Under Load as follows:
Do not close the tester valve fully when performing this test. In this
test, the hydraulic tester is positioned in an unprotected part of the
steering circuit.
Pump damage can occur if the fluid flow is fully restricted by fully
closing the tester flow control valve.
A. Monitor the tester pressure gauge carefully while you slowly close the
flow control valve until you get 5,500 kPa (800 psi).
B. Record the tester pressure and flow readings under load.
12. Press the engine speed to low speed (1,175 to 1,225 rpm) position and
shut off the engine.
13. The under load test flow reading (step 11B) should not drop more than 15%
when compared to the no load test flow reading (step 10A). A difference in
flow of more than 15%, or the inability to achieve specified pressure may
indicate:
A. A restriction in the pump inlet line.
B. The gear pump (P3) is worn and should be repaired or replaced; refer to
Servicing the Gear Pump (page 4–107)
14. After you complete the testing, shut off the engine, and then release pressure
from the hydraulic system; refer to
System (page 4–6).
15. Disconnect the tester, and connect the removed hydraulic tube.
16. Start the engine, check for hydraulic-fluid leaks, repair any leaks as required,
and fill the hydraulic tank with the correct quantity of new hydraulic fluid
before returning the machine to service.
17. Lower and secure the operator seat.
CAUTION
Releasing Pressure from the Hydraulic
Page 4–77 Hydraulic System: Testing the Hydraulic System