Kohler COMMAND CV17-745 Service Manual page 170

Kohler Engine Parts Call K&T 606-678-9623 or 606-561-4983
Section 10
Inspection and Reconditioning
Crankcase Breather System
The breather system is designed to control the amount
of oil in the head area and still maintain the necessary
vacuum in the crankcase.
Figure 10-19. Crankcase with Breather Reed.
A spring steel reed and stop is mounted on each bank
of the crankcase, between the lifter bores (see Figure
10-19). When the pistons move downward, air is
pushed past the reeds into the cylinder head cavities.
On the #2 cylinder, the upper end of the head is
completely sealed by the rocker cover, so a low,
positive pressure is created in the head cavity. The #1
rocker cover has a hole in it for venting. The bottom
nipple of an oil separator canister is fitted into the hole
with a grommet. From the top nipple of the canister, a
breather hose goes back to the air cleaner base. The
air moving into the #1 head cavity is filtered through
the oil separator and then is drawn into the air intake
(see Figure 10-20).
The upward travel of the pistons closes the reeds and
creates a low vacuum in the lower crankcase. The
combination of low pressure above and low vacuum
below forces any accumulated oil out of the #2 head
area into the crankcase. On the #1 bank you have
atmospheric pressure above and vacuum below, again
drawing any oil toward the crankcase.
10.14
Figure 10-20. Oil Separator.
Governor Cross Shaft Oil Seal
If the governor cross shaft seal is damaged and/or
leaks, replace it using the following procedure.
Remove the oil seal from the crankcase and replace it
with a new one. Install the new seal to the depth
shown in Figure 10-21 using a seal installer.
2.0 mm (0.0787 in.)
Figure 10-21. Installing Cross Shaft Oil Seal.
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Governor Cross
Shaft Seal