Toro 30821 Service Manual page 85

Procedure for Gear Pump (P1) Flow Test:
2
Note: Over a period of time, the gears and wear plates
in the pump can wear. A worn pump will by pass oil and
make the pump less efficient. Eventually, enough oil loss
RIGHT
will occur to cause the cutting unit motors to stall under
1
heavy cutting conditions. Continued operation with a FRONT
worn, inefficient pump can generate excessive heat and
cause damage to the seals and other components in the
hydraulic system.
1. Make sure hydraulic oil is at normal operating tem-
perature by operating the machine for approximately 10
minutes.
2. Park machine on a level surface with the cutting units
lowered and off. Make sure engine is off and the parking
brake is engaged.
Figure 61
1. Gear pump (P1) 2. To hydraulic manifold
3. Read Precautions for Hydraulic Testing.
4. Disconnect hose connection on the gear pump (P1)
leading to port (P1) on the hydraulic manifold (Fig. 61).
5. Install tester in series with the gear pump and the dis-
connected hose leading to port (P1) on the hydraulic
manifold.
6. Make sure the flow control valve on the tester is fully
open.
7. Start engine and move throttle to full speed (3050 +
50 RPM). Do not engage the cutting units.
IMPORTANT: In this test, the hydraulic tester is
positioned before the manifold relief valve. Pump
damage can occur if the oil flow is fully restricted by
fully closing the tester flow control valve. Do not
close tester valve fully when performing test.
8. Watch pressure gauge carefully while slowly closing
the flow control valve until 2000 PSI is obtained. Do not
close tester load valve fully. Verify with a phototac that
the pump speed is 3100 RPM while maintaining 2000
PSI.
9. Flow indication should be 11.8 GPM minimum.
10.Shut off engine.
11. Disconnect tester from gear pump fitting and hose.
Reconnect hose to the pump.
12.If flow was less than 11.8 GPM or a pressure of 2000
PSI cannot be obtained, check for restriction in the pump
intake line. If line is not restricted, remove gear pump
(P1) and repair or replace as necessary.
Groundsmaster 3500- D Page 4 - 45 Hydraulic System (Rev. G)