4.8
DETROIT DIESEL 53
VENTILATING SYSTEM
Harmful vapors which may be formed within the
engine are removed from the crankcase. gear train
and valve compartment by a continuous, pressurized
ventilating system.
A slight pressure is maintained in the engine
crankcase by the seepage of a small amount of air
from the airbox past the piston rings. This air sweeps
up through the engine and is drawn off through a
crankcase breather.
In-line engines are equipped with a breather assembly
attached to the valve rocker cover (Fig. 1) or a
breather assembly mounted on the flywheel housing
(Fig. 2).
Fig. 1 - Typical Crankcase Breather Mounting
(In-line Engine)
of clogging. This can best be done by removing the
tube from the engine. washing it with a Suitable
Service
solvent and drying it with compressed air.
It is recommended that the breather tube be inspected
The wire mesh pad (element) in the breather
and cleaned. if necessary, to eliminate the possibility
Fig. 2 - Crankcase Breather Mounting and Details (In-Line Engine)
December, 1970 SEC. 4.8 Page 1