INTRODUCTION TO THE HMMWV - OD1615 - LESSON 1/TASK 2
Air Induction System
The air induction system performs two vital functions. Since all internal
combustion engines require a mixture of fuel and air to be introduced into
the combustion chamber at some point in their operation, some method must be
devised to induct fuel into the engine and eventually into the combustion
chamber. This is the first and primary job of the air induction system.
The second job of the air induction system is to filter the air that has
accomplished through the use of an air filter.
From the previous paragraphs concerning the air induction system, the
following statement can be made concerning its function: "the air induction
system filters the outside air and directs it to the engine".
induction system on the HMMWV consists of the following components:
entry stack with raincap, paper air filter element, air filter canister, air
duct hose, air to manifold duct, and an air restriction gage.
The air filter canister and intake stack are located on the right side of
the vehicle, forward of the windshield and just to the rear of the engine
The filter paper filter element is secured in the canister
with a 5/8 inch nut; the canister cap itself is secured with a clamp.
As the air enters the intake stack, it passes through the filter element
where impurities such as dirt and dust are removed. From there, it passes
through the air to manifold duct which is secured to the intake manifold and
connected to the air filter canister by the air duct hose.
As the air
passes through the air to duct manifold, it passes the air restriction
sensor. The sensor is connected to the air restriction gage, located on the
left side of the instrument panel. The sensor records the amount of dust in
the air as it leaves the air filter. If the air contains too much dust, the
indicator will read in the red zone.
This means that the filter element
should either be replaced or, if replacement is not possible, cleaned. The
gage is equipped with a reset button that returns the float in the gage to
its normal position.