D21d
Maintenance Instructions
Checking and Servicing
77
Radiator Hoses and Clamps
Inspect the radiator hoses
every 200 hours
for
deterioration or damage. Also check the tightness
of the hose clamps. Good preventive maintenance
calls for complete
replacement
of the radiator
hoses and clamps
every two (2) years.
Engine Valve Clearance
Check and adjust the Kubota engine valve clear-
ance
every 800 hours.
Refer to the Kubota
Engine Owner’s Manual and Workshop Manual for
specifications and procedure to check the valve
clearance. For engine servicing, contact an autho-
rized Kubota engine dealer or a trained engine
technician.
IMPORTANT:
Always use the proper engine ser-
vice manual when working on the engine. Improp-
er engine maintenance or adjustments will
adversely affect engine operation, performance,
and durability and may
VOID
the warranty.
Fuel Injection Nozzle Pressure
Check and adjust the Kubota diesel engine fuel
injection nozzle pressure
yearly
or
every 1000
hours
(or in case of low power). Refer to the
Kubota Workshop Manual for specifications and
procedures to check nozzle pressure. For engine
servicing, contact an authorized Kubota engine
dealer or a trained engine technician.
IMPORTANT:
Always use the proper engine ser-
vice manual when working on the engine. Improp-
er engine maintenance or adjustments will
adversely affect engine operation, performance,
durability, and may
VOID
the warranty.
WARNING
The fuel oil injection system operates un-
der high pressure and can penetrate the
skin and result in serious injury. Unquali-
fied persons should not remove or attempt
to adjust a pump injector, nozzle, or any
part of the fuel injection system.
Transmission Control Setting
On a
yearly
interval or when an out-of-adjustment
condition is observed, check the transmission
control for proper function as follows:
Neutral-Park
With the mower parked on level ground, start and
run the engine, first at idle and then normal operat-
ing speeds. With the FSC in the
NEUTRAL-PARK
position, there should be no movement of either
drive tire. If the tire(s) are “creeping” forward or
reverse, refer to
Adjustments for Transmission
Control in Neutral Function Adjustment - Step 4 on
page 89.
Straight Ground Tracking
Check for straight ground track by driving on a
smooth, level surface with hands off the steering
levers. Set the FSC at different speeds and
observe if the mower moves in a straight line (use
a cement joint or other line on the ground for refer-
ence). If the machine is drifting to the right or left,
refer to
Adjustments for Transmission Control in
Straight Ground Travel Adjustment - Step 5 on
page 90.
Blade Brake Action
WARNING
It is important to check and maintain blade
brake action for safe operation of the ma-
chine.
Check the function of the cutter blade brake (and
blower brake on GHS models) by engaging the
blade clutch (PTO), operating the engine at full
throttle, then disengaging the clutch and measur-
ing how quickly the blades stop. Watch the rota-
tion of the blade drive shaft and blower pulley as a
visual indication that movement has stopped. If
the brake is
working properly, all rotation will
stop five (5) seconds after disengagement
of
the clutch. If the brake system malfunctions—
blades do not stop in five (5) seconds—adjust or
repair the brake before operating the mower. Con-
tact your Walker dealer for this service or refer to
Adjustments for
Clutch Disengagement/Brake
Action on page 91.
