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LUBRICATION
0-1 5
CONNECTING
INTAKE
MANIFOLD
/
I
INTAKE
MANIFOLD
7
u
S I X
-
CYLINDER ENQINES
u
V - 8
E N G I N E S
NB265D
Fig. 30-Closed
Crankcase Ventilation System
with Closed Type Breather Cap.
On cars equipped with the
silenced
carburetor air
cleaner with a wrapper on the cleaner element the
system should be serviced every six months and the
valve replaced once a year. The air cleaner element
and wrapper should be replaced every two years.
On cars with high performance engines equipped
with
non-silenced
air cleaners without a wrapper, the
system should be serviced with every engine oil
change and the valve and air cleaner element re-
placed every year.
This service will be required more frequently if
the vehicle is used extensively for short-trip driving
less than 10 miles with frequent idling, such as in
city traffic.
SERVICE PROCEDURES
With the engine idling, remove the ventilator valve
and cap assembly from the rocker cover (Fig. 30). If
the valve is working freely, a hissing noise will usu-
ally be heard as air passes through the valve, and
a
strong vacuum should be felt when a finger is placed
over the valve inlet.
If the valve is working properly, reinstall the ven-
tilator valve and cap assembly and remove the oil
filler pipe breather cap. With the engine still idling,
loosely hold a piece of stiff paper or a parts tag over
the oil filler pipe. After allowing a few seconds for
crankcase pressure to reduce, the paper should be
drawn against the filler pipe with a noticeable force.
If this occurs, a final check should be made to be cer-
tain the valve shuttle is free. Shut off the engine, re-
move the valve and shake it vigorously. A clicking
noise should be heard if the valve is satisfactory and
no further service is necessary.
If the valve does not click when shaken, or the pa-
per is not drawn against the filler pipe, the valve
should be replaced and the system rechecked.
NOTE:
Do not attempt to clean the valve. Replace
it with a new valve.
On 170 cubic inch engines use Ventilator Valve
identified by either a number
"6"
stamped on the
end, a stop on the end face, or a white end washer.
For all other engines use valves that have either the
letter
"H"
stamped on the end, a flat end, or a black
end washer.
Remove the ventilator valve hose (Fig. 30) from
the valve cap, inspect it and clean, if necessary.
Also, remove the breather cap hose (Fig. 30) from
the cap and the air cleaner. Inspect the hose and clean
it if necessary.
Remove the closed breather cap (Fig. 31) and dis-
connect the hose leading from the air cleaner. Clean
the cap in solvent. Lubricate the filter element through
the vent tube with SAE 30 engine oil.
Remove the carburetor. Hand turn a JA inch drill
through the passages to dislodge solid particles. Blow
passages clean.
CAUTION: Under no circumstances should metal
be removed. Use a smaller drill if necessary.
CARBURETOR AIR CLEANER-WITH
WRAPPER
To clean the filter it should be removed from its
container. Remove the wrapper from the element
(Fig. 32). Wash the wrapper in kerosene or other suit-
able solvent to remove all dirt and oil. Shake or blot
dry. Gently blow out the dirt from the element with
compressed air. The air nozzle should be held about
two inches from the inside screen (Fig.
35).
__
NK577
Fig. 31-Closed
Crankcase Ventilation System
with Closed Type Breather
Cap.
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