Service Manual

Groundsmaster 360 Hydraulic SystemPage 4 − 33
Which Hydraulic Tests Are Necessary?
Before beginning any hydraulic test, identify if the prob-
lem is related to the traction circuit, PTO circuit, lift/lower
circuit or steering circuit. Once the faulty system has
been identified, perform tests that relate to that circuit.
1. If a traction circuit problem exists, consider perform-
ing one or more of the following tests: Charge Relief
Valve Pressure, Traction Relief Valve Pressure, Trans-
mission Piston Pump Flow and/or Rear Wheel Motor Ef-
ficiency.
2. If a PTO circuit problem exists, consider performing
the PTO Pressure Valve Test.
3. If a lift/lower circuit problem exists, consider perform-
ing one or more of the following tests: Implement Relief
Pressure, Gear Pump Flow and/or Lift Cylinder Internal
Leakage.
4. If a steering circuit problem exists, consider perform-
ing one or more of the following tests: Implement Relief
Pressure and/or Gear Pump Flow.
Traction System Operation Testing
Because the Groundsmaster 360 traction system uses
two (2) separate but interconnected circuits, it can be
difficult to identify which circuit is causing a problem and
what hydraulic tests should be performed. Use the fol-
lowing operation tests and suggestions before perform-
ing the hydraulic tests described in this section.
1. If a 2WD machine does not track in a straight line,
look for a problem with components that affect the lag-
ging traction side of the machine. During operation, a
2WD machine might steer toward the weaker side of the
traction system. Because the piston pump swash plates
are controlled by traction control linkage movement, if
one swash plate is rotated more than the other, the ma-
chine might not track in a straight line.
2. On 2WD machines, drive up a moderate incline, stop
the engine, place the traction pedal in the neutral posi-
tion and allow the transmission to hold the machine in
place (parking brake not applied). The machine should
remain stationary on the incline or drift slowly back-
wards in a straight line. If one of the transmission traction
circuits is faulty, the machine will roll backwards toward
the lagging traction circuit.
3. On 2WD or 4WD machines, wheel speed should be
the same on both rear wheels. Make sure hydraulic oil
is at normal operating temperature. With the machine
drive wheels raised up off the ground and the machine
securely supported with jack stands, have an operator
in the seat move the traction control pedal to the full for-
ward speed. Check the rotational speed of both rear
wheels. The wheel speed of both rear wheels should be
approximately the same.
4. If any of these operation tests suggest a traction sys-
tem problem, check the following before performing hy-
draulic tests.
A. Check oil level in the hydraulic tank to make sure
that oil level is correct.
B. Check brake adjustment to make sure that the
brakes are not dragging.
C. Check that both transmission bypass valves are
seated.
D. Check that traction pedal is rotating the transmis-
sion pump swash plates equally.
E. Check for free movement of all traction linkage
control components.
Hydraulic
System