Volvo B5254T3 Manual page 21

The gasket between the lower intake manifold and the cylinder head is a double gasket with a non-
return valve.
The gasket has a non-return valve (reed valve) beside each intake port to stop the crankcase gases
from running back into the oil trap.
Intake Manifold Upper Section
The upper intake manifold is plastic.
Each cylinder has an intake pipe that comes off a plenum chamber.
Air Cleaner
The air cleaner and air cleaner housing are designed to minimize drops in pressure and to be as
compact as possible.
•
The air cleaner housing and control module box are integrated into one unit.
The air cleaner is a cassette that is inserted vertically and secured with 2 bolts.
•
The air cleaner unit is mounted on three brackets.
•
A spring-loaded valve is located beside the air cleaner and opens when the pressure drops below 6
kPa if the air intake pipe is restricted.
Engine Cooling Fan
6 fixed speeds
7 blades