Walker MDD (20.9 HP) - Manual (Page 58)

Maintenance Instructions
LUBRICATION
54
Hydrostatic Transmission Fluid
Checking Hydrostatic Transmission Fluid Level
Hydrostatic transmission fluid level should be
checked every 25 hours of machine operation. It is
preferable to check the fluid level when fluid is
cold. Check fluid level as follows:
1. Park the mower on a level surface. Stop the
engine and wipe dirt and contaminants from
around the reservoir cap and air bleed plug.
IMPORTANT: Before removing the reservoir
cap, clean any dirt from around it. Any dirt or
contaminants entering the transmission will ac-
celerate wear and eventually cause loss of pow-
er to the drive wheels.
2. Remove the reservoir cap and check the level
of the fluid. The reservoir has a fluid level COLD
mark and HOT mark. The reservoir oil level
should ALWAYS be at or above the COLD
mark and NEVER above the HOT mark.
Transmission Reservoir
and Air Bleed Plug Location
3. If the fluid is below the COLD mark (or the trans-
mission is not performing properly), loosen the
air bleed plug (located on the top of transmis-
sion case next to the plastic reservoir).
a. If a small amount of fluid leaks from around
the air bleed plug:
* The transmission is full of fluid.
* Tighten the plug and fill the reservoir to
the COLD level mark.
b. If no fluid leaks from around the air bleed
plug:
* Slowly add fluid into the reservoir until
fluid starts to leak from around the plug.
(Transmissions are serviced from the
factory with Mobil 1 (15W50) Synthet-
ic Oil). When it is necessary to add flu-
id, refer to
Specifications for the proper
fluid.
* As soon as there is fluid leaking from
around the air bleed plug, tighten the
plug and fill the reservoir to the COLD
level mark. Wipe any excess oil off of
the transmission housing.
IMPORTANT: DO NOT overfill the transmission
reservoir. This will result in oil leaking out of the res-
ervoir cap vent when the transmission warms up. It
is preferable to add fluid to the transmission when it
is cold and make sure the oil is not above or be-
low the COLD level mark.
IMPORTANT: The transmission reservoir has a fine
mesh screen in the bottom to trap dirt and foreign
particles from entering the transmission. When fill-
ing the reservoir, fluid will flow quite slowly through
this screen; so it is essential that there is fluid at the
bleed plug before the transmission is considered
full.
IMPORTANT: Any attempt to remove or in any way
alter the filtering screen in the transmission reservoir
could cause damage to the transmission and will
VOID any transmission warranty.
Changing Hydrostatic Transmission Fluid
The hydrostatic fluid should be changed every 1000
hours or two (2) years. Also, the fluid should be
changed if the natural color of the fluid has become
black or milky (indicating possible overheating
or water contamination of fluid). The transmission is
refilled using the factory service fluid noted in
TRANSMISSION
Specifications . The fluid is
changed as follows:
1. Park the mower on a level surface and stop the
engine.
2. Remove the lower drain plug and the air bleed
plug. Allow the fluid to drain out.
IMPORTANT: Clean any dirt from around the
plugs and reservoir cap before removing them.
Reservoir Cap
Hot
Level
Cold Level
Air Bleed
Plug