Toro Groundsmaster 360 Service Manual page 69

The Charge Relief Valve Pressure Test should be per-
formed if a traction circuit problem is identified. This test
will determine if the traction charge circuit is functioning
correctly.
Procedure for Charge Relief Valve Pressure Test:
1. Make sure hydraulic oil is at normal operating tem-
perature and hydraulic tank is full.
2. 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.
3. Park machine on a level surface with the cutting deck
lowered and off. Apply parking brake. Make sure engine
is off.
4. Read Precautions for Hydraulic Testing listed at the
beginning of this section.
5. Thoroughly clean charge pressure test port on right
side of transmission (Fig. 27). Connect a 1000 PSI (70
bar) pressure gauge with an attached hydraulic hose to
the transmission charge pressure test port.
6. Start engine and run at low idle speed (1300 RPM).
Check for any hydraulic leakage from test connections
and correct before proceeding with test.
7. With engine running, move throttle to full speed
(3100 to 3150 RPM).
8. Pressure gauge should read from 105 to 135 PSI
(7.2 to 9.3 bar). Record test result.
9. If charge relief pressure specification is not met,
consider the following transmission issues (see Trans-
mission Service in the Service and Repairs section of
this chapter):
A. The transmission charge relief valve is faulty. Re-
pair or replace the charge relief valve.
B. A transmission traction relief valve or flushing
valve is leaking or damaged.
C. The charge pump in the transmission is faulty
(PTO operation would also be affected).
Groundsmaster 360
10.Next, determine charge pressure under traction load
by operating the machine in a direct forward and reverse
direction. Make sure that engine is running at full speed
(3100 to 3150 RPM).
NOTE: When applying brakes, make sure that parking
brake latch is not depressed. Engine will stop if parking
brake latch is pressed.
11. Firmly apply the brakes and press the traction pedal
in the forward direction and then to reverse while moni-
toring the pressure gauge. Release traction pedal to
neutral, stop engine and record test results.
A. The charge pressure should drop no more than
15% from initial test reading (Step 8 above) as the
machine is moving (e.g. if initial charge pressure was
120 PSI (8.3 bar), charge pressure while machine is
moving should be above 102 PSI (7.0 bar)).
B. A pressure drop of more than 15% indicates a
traction circuit leak (e.g. a leaking transmission
check valve, a worn/damaged transmission piston
pump). If charge pressure is good under no load, but
drops below specification when under traction load,
the transmission piston pump(s) should be sus-
pected of wear or damage. When a piston pump is
worn or damaged, the charge pump is not able to
keep up with internal leakage in the traction circuit.
12.Stop machine and shut off engine.
13.Relieve hydraulic system pressure (see Relieving
Hydraulic System Pressure in the General Information
section). Remove pressure gauge from transmission
charge pressure test port.
Page 4 - - 35
FRONT
Charge Pressure
Test Port
Figure 27
Hydraulic System