Service Manual

Rev. A
Groundsmaster 360 Hydraulic SystemPage 4 − 37
The Traction Relief Valve Pressure Test should be per-
formed if a traction circuit problem is identified. This test
will determine if a transmission relief valve is operating
correctly.
Procedure for Traction Relief Valve Pressure
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
lowered and off. Make sure engine is off and that the
parking brake is not applied.
3. Read Precautions for Hydraulic Testing listed at the
beginning of this section.
4. Thoroughly clean area surrounding traction circuit
hoses on top of transmission (Fig. 28 or 29).
5. Determine which traction relief valve is to be tested.
Disconnect hydraulic hose from transmission pump out-
let fitting for relief valve to be tested (Fig. 28 or 29):
Relief Valve to be Tested
Pump Outlet
Right Side Forward Port A
Right Side Reverse Port B
Left Side Forward Port C
Left Side Reverse Port D
NOTE: Pump outlet ports are not identified on the pump
housing. Use illustration in Figure 28 (2WD machine) or
29 4WD machine) to identify pump ports.
6. Install a tee fitting between the disconnected hydrau-
lic hose and the transmission fitting. Install a 5000 PSI
(350 bar) pressure gauge to the tee fitting.
7. Disconnect balancing hose from transmission fitting
closest to transmission pump outlet fitting for relief valve
to be tested (Fig. 28 or 29). Install steel cap on fitting and
steel plug in balancing hose.
8. Start engine and run at low idle speed (1300 RPM).
Check for any hydraulic leakage from test connections
and correct before proceeding with test.
9. Move throttle to full speed (3100 to 3150 RPM).
Figure 29
Port C
Port D
Port B
Port A
Balancing Hose
Balancing Hose
4WD Machine
10.Sit on seat and move machine against an immovable
object (e.g. wall) to prevent movement of the machine.
CAUTION
Use extreme caution when performing test. The
drive wheels will be trying to move the machine
during test.
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 brakes to prevent the rear wheels from
rotating and then slowly depress the traction pedal in the
direction to be tested (forward or reverse). While press-
ing traction pedal, carefully watch the pressure gauge
needle. As the traction relief valve lifts, the gauge needle
will momentarily stop. Traction system pressure as the
relief valve opens should be:
3900 to 4100 PSI (269 to 282 bar) in either forward
or reverse
NOTE: It may be difficult to achieve traction circuit relief
pressure. If traction pedal is depressed slowly, it is more
likely that relief pressure can be obtained.
12.Release traction pedal to neutral, stop engine and
record test results.
NOTE: The forward relief valves for the two (2) trans-
mission pump circuits are identical and thus can be in-
terchanged. The reverse relief valves are also identical.
The forward relief valves, however, are different than the
reverse relief valves so do not interchange forward and
reverse relief valves. The relief valve locations are
shown in Figure 30.
Hydraulic
System