Toro Groundsmaster 3505-D Service Manual page 71

Procedure for Gear Pump (P1) Flow Test:
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
will occur to cause the cutting unit motors to stall under
heavy cutting conditions. Continued operation with a
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.
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.
3. Read Precautions for Hydraulic Testing.
WARNING
Before disconnecting or performing any work
on the hydraulic system, all pressure in the
system must be relieved. See Relieving Hy-
draulic System Pressure in the General Infor-
mation section.
4. Disconnect hose connection on the gear pump (P1)
leading to port (P1) on the hydraulic manifold (Fig. 27).
5. Install hydraulic tester (pressure and flow) in series
with the gear pump and the disconnected 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 tester 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. Record test results.
Groundsmaster 3505--D
11. 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.
12.Relieve hydraulic system pressure (See Relieving
Hydraulic System Pressure in the General Information
section). Disconnect tester from gear pump fitting and
hose. Reconnect hose to the pump.
2
RIGHT
FRONT
1. Gear pump (P1)
Page 4 - - 41
1
Figure 27
2. To hydraulic manifold
Hydraulic System