6-12. AIR BOX DRAINS - Continued
Testing Air Flow.
Do not stand in front of vehicle when testing air box
pressure. Brake could release and vehicle could jump
forward causing personal injury or death.
Do not operate vehicle with transmission engaged and
at maximum rpm for more than 15 seconds at a time.
Transmission oil heats up quickly and could cause
transmission to fail.
Remove plug (1) and install air pressure gauge
Chock wheels, set parking brake and foot brake.
Low air box pressure can be caused by an obstruction
in the air inlet system, dirty or damaged air cleaners,
damaged blower rotors, or an air leak from the air box
(such as leaking end plate gaskets). High air box
pressure reading can be caused by partially plugged
Connect batteries (see para 4-114).
When told, other person starts engine, warms up engine for 5 minutes, then shifts transmission into
Check airbox pressure. Pressure shall be 9 psi (62 kPa) at 1200 rpm, 16 psi (110 kPa) at 1800 rpm
and 20 psi (138 kPa) at 1950 rpm.