Cadillac 1967 VVI Data Book page 178

Positive Crankcase Ventilation (P.C.V.)
The positive Crankcase Ventilation system, which is sjtandard
equipment on your vehicle, helps control air pollution caused
by crankcase blow-by gases. The P.C.V. system connects the
crankcase and intake manifold of the engine and exhaust blow-
by gases are returned through this system to the combustion
chamber where they are reburned. Periodic inspection and
required servicing of your P.C.V. system assures a cleaner,
better-performing, longer-lasting engine and almost 100%
elimination of any air pollution caused by crankcase blow-by
gases. A plugged P.C.V. system can cause condensation of
blow-by gases in the crankcase, resulting in the formation of
acids, sludge build-up and oil dilution. Every 12 months or
12,000 miles, whichever occurs first, the P.C.V.: valve should
be replaced. Also, all hoses, fittings and the inlet air filter
should be inspected, cleaned and replaced, if necessary.
NOTE: If the positive crankcase ventilator Valve should
become clogged, the engine idle will be adversely affected.
Therefore, if the engine idle becomes too slow or rough, the
ventilator valve should be checked before any carburetor
adjustments are made to compensate for the trouble.
Air Injection Reactor (A.I.R.)
The Air Injection Reactor System is an exhaust emission con-
trol system installed on all domestic 1967 General Motors cars
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(and some trucks) destined for initial registration in the State of
California. This air pollution control system is entirely separ-
ate from the Positive Crankcase Ventilation System. It is
designed to reduce air pollution caused by engine exhaust
tailpipe gases by "treating" the unburned hydrocarbons and
carbon monoxide as they are expelled from the combustion
chamber into the exhaust manifold. A sealed bearing pump,
driven by the engine, compresses, distributes and injects clean
filtered air at the exhaust port of each cylinder. Here it com-
bines with the unburned hydrocarbons and carbon monoxide
at high temperatures in a chemical reaction, producing a
"treated" exhaust that is below the maximum allowable level
for air pollution from this source. This does not reduce the
danger of inhaling any concentration of carbon monoxide in a
confined area. See Page 62 for carbon monoxide warning.
The A.I.R. pump filter should be serviced every 12 months
or 12,000 miles, whichever occurs first, by removing the filter
element, washing in kerosene, dipping in SAE 10W-30 oil,
and squeezing to remove excess oil.
Check condition and adjustment of pump pulley belt annu-
ally. Clean and oil metal gauze strainer, located on wall of
carburetor air cleaner at time of engine oil change.
Also, the annual engine tune-up recommended for normal
engine efficiency, operation, and performance is important for
the A.I.R. system's continued effectiveness.