General. Four drainvalves, located on right side of vehicle next to toolbox, are used to drain moisture from
Turn drainvalves (1) counterclockwise
to drain moisture from:
reservoir drainvalve 1.
reservoir drainvalve 3.
Secondary airbrake system air
reservoir drainvalve 4.
After all moisture has been drained and only air is coming out, turn drainvalves (1) clockwise to close.
Final Inspection. Make sure drainvalves (1) are closed tight to prevent air from escaping. If air escapes
after drainvalves are closed tightly, notify unit maintenance immediately.
TRANSMISSION OIL LEVEL
When checking transmission oil level, do not permit dirt, dust or grit to enter transmission filler tube. Make
sure dipstick handle and end of filler tube are clean to prevent internal transmission damage.
General. The transmission oil level is checked weekly with engine running at idle, transmission in neutral,
and parking brake applied. In M939/A1 series vehicles, transmission dipstick (3) is located under access door (4) in center
of cab floor. In M939A2 series vehicles, transmission dipstick (3) is on right side of engine compartment.