Harmful vapors which may be formed within the engine
are removed from the crankcase, gear train and valve
compartments by a continuous pressurized ventilating
A slight pressure is maintained in the engine crankcase
by the seepage of a small amount of air from the air box
past the piston rings. This air sweeps up through the
flywheel housing and is admitted to the valve
compartment through cavities in the lifter brackets and
Ventilating air in the valve compartment is drawn off via
the governor control housing through a breather
attached to the side of the cylinder block (Fig. 1).
Inspect and clean the breather and baffle, if necessary,
to eliminate the possibility of clogging. Remove the
breather and baffle from the cylinder block. Wash with
a suitable solvent and dry with compressed air.
The steel mesh pad should be removed and cleaned
Figure 1. Breather Mounted on Cylinder Block
periodically (refer to Page 10-11-3).