Toro Groundsmaster 7200 Service Manual page 65

The Transmission Piston Pump Flow Test should be
performed if a traction circuit problem is identified. This
test will determine if hydraulic flow from a transmission
piston pump is correct.
Procedure for Transmission Piston Pump Flow
Test:
1. Make sure hydraulic oil is at normal operating tem-
perature. Also, make sure that traction drive is correctly
adjusted for the neutral position.
WARNING
Before disconnecting or performing any work on
the hydraulic system, all pressure in the system
must be relieved. See Relieving Hydraulic System
Pressure in the General Information section.
2. Park machine on a level surface with the cutting deck
(or implement) lowered and off. Make sure engine is off.
3. Read Precautions for Hydraulic Testing listed at the
beginning of this section.
WARNING
Before jacking up the machine, review and follow
Jacking Instructions in Chapter 1 – Safety.
4. Raise and support machine with jack stands so that
both rear wheels are off the ground. In this test, the rear
wheels need to spin freely to allow hydraulic flow
through the traction circuit. Make sure that the parking
brake is not applied.
5. Thoroughly clean transmission area surrounding
traction circuit hoses on top of transmission (Fig. 16).
Determine which piston pump is to be tested.
6. Disconnect hydraulic hose from transmission pump
outlet fitting for piston pump to be tested (Fig. 16):
Piston Pump to be Tested
Right Side Pump
Left Side Pump
7. Install hydraulic tester (pressure and flow) in series
between the pump outlet fitting and the disconnected
hose. Make sure that the tester flow arrow points from
the pump outlet and toward the hose. Make sure the
flow control valve on the tester is fully open.
Groundsmaster 7200/7210
8. Sit in the operator seat, start engine and run at low
idle speed (1500 to 1650 RPM). Check for any hydraulic
leakage from test connections and correct before pro-
ceeding with test.
IMPORTANT: Do not run engine at full speed when
performing this flow test using Toro Hydraulic Tes-
ter (Pressure and Flow) (TOR214678). Traction
pump output at full engine speed can damage hy-
draulic tester.
9. Using a phototac to measure engine speed, move
throttle so engine speed is 2800 RPM (not full speed).
10.Have operator slowly push traction lever for pump
being tested to fully forward position. Leave other trac-
tion lever in neutral position.
11. Slowly close tester flow control valve until pressure
gauge reads 1000 PSI (69 bar). Verify with a phototac
that the engine speed is still 2800 RPM.
12.Observe flow gauge. TESTER READING should be
approximately 13.3 GPM (50.3 LPM) for a traction pump
in good condition.
13.Open tester flow control valve, release traction lever
to the neutral position and stop engine. Record test re-
sults.
14.Normal traction pump flow is 13.3 GPM (50.3 LPM).
Lower pump flow would result in reduced traction circuit
performance. If flow is less than 11 GPM (41.6 LPM) or
a pressure of 1000 PSI (69 bar) cannot be obtained:
15.If transmission piston pump flow specification is met,
Pump Outlet
and a traction circuit problem has been identified, con-
sider that a wheel motor is worn or damaged (see Wheel
Port A
Motor Efficiency Test in this section).
Port C
16.Relieve hydraulic system pressure (see Relieving
Hydraulic System Pressure in the General Information
section). Disconnect tester from transmission fitting and
hose. Reconnect hydraulic hose to transmission port fit-
ting.
17.If necessary, repeat flow test for other transmission
piston pump.
Page 4 – 29
A. The traction control lever may need adjustment.
B. If the engine speed drops excessively as the test-
er flow control valve is closed, engine performance
should be evaluated (see Chapter 3 – Kubota Diesel
Engine).
C. If engine speed does not drop and pressure and
flow specifications are not met, the tested transmis-
sion piston pump needs to be inspected, repaired or
replaced as necessary.
Hydraulic System