Toro Groundsmaster 4300-D Service Manual page 148

Test Procedure (continued)
Hydraulic System: Testing the Hydraulic System
8. Verify the pump flow at No Load as follows:
Record the tester pressure and flow readings at no load. Unrestricted pump
output should be approximately 11.9 L/minute (3.2 gallons/minute).
9. 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 before the manifold relief
valve.
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 8,274 kPa (1,200 psi).
B. Record the tester pressure and flow readings under load.
10. Press the engine speed switch to low speed (1,175 to 1,225 rpm) position
and shut off the engine.
11. The under load test flow reading (step 9B) should not drop more than 15%
when compared to the no load test flow reading (step 8). 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 (P4) is worn and should be repaired or replaced; refer to
Servicing the Gear Pump (page 4–107)
12. After you complete the testing, shut off the engine, and then release pressure
from the hydraulic system; refer to
System (page 4–6).
13. Remove the tester, and connect the hydraulic hose to the gear pump (P4)
outlet.
14. 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.
15. Install the floor plate, lower and secure the operator seat.
CAUTION
Releasing Pressure from the Hydraulic
Page 4–86 Groundsmaster ® 4300-D
16226SL Rev C