Service Manual

Table Of Contents
Groundsmaster 7200/7210Hydraulic System Page 4 – 8
Traction Circuit (Closed Loop) Component Failure
The traction system on Groundsmaster 7200 and 7210
machines consists of two identical and independent
closed loop traction circuits. If a component in one of
these traction circuits (e.g. wheel motor or transmission
piston pump) should fail, debris and contamination from
the failed component will circulate throughout the trac-
tion circuit. This contamination can damage other com-
ponents in the circuit so it must be removed to prevent
additional component failure.
If a component failure occurs in one of the traction cir-
cuits, it is critical to disassemble, drain and thoroughly
clean the entire traction circuit (transmission piston
pump, hydraulic hoses and wheel motor). This proce-
dure will ensure that all contamination is removed from
the circuit. If any debris remains in the traction circuit and
the machine is operated, the debris can cause addition-
al component failure.
An additional step for removing all traction circuit con-
tamination would be to temporarily install a high pres-
sure hydraulic oil filter (see Special Tools) into the circuit.
The filter could be used when connecting hydraulic test
gauges in order to test traction circuit components or af-
ter replacing a failed traction circuit component (e.g.
wheel motor or transmission piston pump). The filter will
ensure that contaminates are removed from the closed
loop and thus, do not cause additional component dam-
age.
Once the filter has been placed in the traction circuit,
place the machine on jack stands and operate the trac-
tion circuit to allow oil flow through the circuit. With the
machine raised off the ground, the traction circuit will
have maximum oil flow at minimum pressure to mini-
mize damage from any remaining contamination. The
filter will remove contamination from the closed loop
traction circuit during operation. Remove the filter from
the machine after contamination has been removed
from the traction circuit.
IMPORTANT: When operating the traction system
with the high pressure filter installed, make sure
that flow is always directed through the filter (e.g. do
not move the traction levers in the reverse direction
if the filter is placed for forward direction flow). If
flow is reversed, debris from the filter will re–enter
the traction circuit.