Engine Systems
CRANKCASE VENTILATION
Fig. 14 - Typical Mounting of Breather
Fig. 13 - Breather Pads and Retainers
Assembly on Valve Rocker Cover
Installed in Cylinder Block
A breather pipe is pressed into or flange mounted on
Harmful vapors which may be formed within the
top of the cylinder block to provide an exit for the
engine are removed from the crankcase, gear train,
crankcase vapors.
and valve compartment by a continuous pressurized
Some engines have an additional breather assembly
ventilation system.
mounted on the flywheel housing or on one of the
Breathing is through two openings in the rear main
valve rocker covers (Fig. 14).
bearing bulkhead of the crankcase, which connects to
a chamber. Two crimped-steel mesh breather pads,
which cover the openings (Fig. 13), filter out the oil as
the vapors pass into the chamber.
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