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

Maintenance Instructions

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 pres­
sure 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 transmission
cooling is to inspect the cooling fans. Replace the
fan(s) if blades are missing or damaged.
Cooling Fan
Hydrostatic Transmission Cooling Fins
70
Cooling Fins

CHECKING/SERVICING

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 electric 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 recovery tank.
If the coolant level is low, remove the radiator cap
and fill to the overflow port level and then fill the re­
covery 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/