Hydrostatic Transmission Cooling Fins; Checking/Servicing; Engine Cooling System; Coolant Level - Walker D21d Operator's Manual

D21d

Hydrostatic Transmission Cooling Fins

Keeping the cooling fins on the hydrostatic trans-
missions clean and free of obstruction is essential
to avoid overheating the transmission fluid and
short ening transmission life. The cooling fins
should be checked every 100 hours and cleaned
if neces sary.
To clean the fins, use compressed air and/or a
pressure washer. The cooling fins extend all the
way around the housing–the fins underneath need
to be clean as well as the more visible fins above.
Also, pay close attention to the area under the
drive pul ley.
IMPORTANT: In case an oil leak develops on the
input shaft, the cooling fan blowing dusty air and oil
on the transmission will quickly pack the cooling
fins with oily dirt. If this condition occurs, replace
the seal immediately to avoid overheating and
dam aging the transmission. The input shaft
assembly and seal are easily replaced without
removing the transmission from the machine.
An additional procedure in maintaining transmis-
sion cooling is to inspect the cooling fans. Replace
the fan(s) if blades are missing or damaged.
Cooling Fins
Hydrostatic Transmission Cooling Fins
Cooling Fan
Maintenance Instructions

CHECKING/SERVICING

DANGER
To prevent accidental starting of the en gine
when servicing or adjusting the ma chine,
remove the key from the ignition switch
and disconnect the electrical plug on the
fuel shut-off solenoid.

Engine Cooling System

Coolant Level

WARNING
NEVER remove the radiator pressure cap
when the engine is hot—hot water could
spray and cause a burn if the cap is taken
off too soon.
Check the coolant level in the coolant recovery
tank and maintain the coolant level between the
FULL and LOW marks on the recovery tank.
When the engine is cold, the coolant level should
be at or slightly above the LOW mark on the recov-
ery tank.
If the coolant level is low, remove the radiator cap
and fill to the overflow port level and then fill the
recovery tank above the LOW mark. Use a pre-
mixed 50/50 solution of antifreeze (ethylene glycol)
and distilled water to fill the cooling system.
IMPORTANT: The coolant solution of antifreeze
and distilled water must be thoroughly pre-mixed
before putting it in the engine (adding pure anti-
freeze into the radiator may cause damage to the
engine by causing overheating).
Cleaning
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