Thermostatically Controlled Air Cleaner - Chevrolet 10 1971 Series Chassis Service Manual

ENGINE FUEL 6M-20
VIEW A — ENGINE OFF
SNORKEL TUBE
VACUUM CHAMBER
CONTROL DAMPER ASSM.
VIEW C -U N DERH O O D TEMPERATURE
ABOVE 128°F
AIR BLEED VALVE OPEN ■
SNORKEL TUBE
AIR INLET
CONTROL DAMPER ASSM.
2„ Remove the wing nut and cover.
3. Loosen the jam nut and unscrew the thermostatic
element.
4. Screw in a new thermostatic element until it just
bottoms on the push rod (with the valve held closed
by the spring). Immerse cover and element in water
of 83°F for two to three minutes, then screw the ele­
ment in further until the cover air valve just begins
to open. Tighten jam nut. Raise water temperature.
Valve should be fully open at 120°F.
5. Replace the cover and wing nut, and the sheet metal
to air cleaner cover hose.

THERMOSTATICALLY CONTROLLED AIR CLEANER

This system (fig. 6A and
carburetor operation and engine warm-up character­
istics. It achieves this by keeping the air entering the
carburetor at a temperature of at least 100°F or more.
The thermostatic air cleaner system includes a tem­
perature sensor, a vacuum motor, and control damper
assembly mounted in the air cleaner, vacuum control
hoses, manifold heat stove and connecting pipes. The
vacuum motor is controlled by the temperature sensor.
The vacuum motor operates, the air control damper
assembly to regulate the flow of hot air and under hood
air to carburetor. The hot air is obtained from the heat
stove on the exhaust manifold.
Inspection
Visual
1. Check for proper and secure connections of heat
pipe and hoses.
2. Check for kinked or deteriorated hoses. Repair or
replace as required.
DIAPHRAGM SPRING
DIAPHRAGM
HOT AIR PIPE
DIAPHRAGM SPRING
HOT AIR PIPE
Fig. 7 A — A ir Cleaner Operation
7A)
is designed to improve
VIEW B - UNDERHOOD TEMPERATURE
BELOW 85°F
DIAPHRAG/|A SPRING
VACUUM CHAMBER
SNORKEL TUBE ^
CONTROL DAMPER ASSM.
VIEW D - UNDERHOOD TEMPERATURE
BETWEEN 85°F AND 1
DIAPHRAGM
VACUUM CHAMBER
SNORKEL TUBE
AIR INLET
CONTROL DAMPER ASSM. I | f Is HOT AIR PIPE
Operational
1. Remove air cleaner cover and install temperature
gauge (Tool J-22973) as close as possible to sensor
(fig. 8A).
Reinstall cover without wing nut. (Temperature
must be below 85°F before proceeding.)
2. With the engine " Off" , observe damper door position
through snorkel opening.
open. If not, check for binds in linkage.
Start and idle engine.
3.
85°F, snorkel passage
damper door begins to of
air cleaner cover and ob
It should be between 85° F
TOOL J-22973
Fig. 8A — Temperatur
AIR BLEED VALVE
. CLOSED
TEMP. SENSING
SPRING
/ DIAPHRAGM
HOT AIR PIPE
AIR BLEED VALVE
TEMP. SENSING
SPRING
Snorkel passage should be
Vith air temperature below
should be closed. When
en snorkel passage, remove
serve thermometer reading,
and 115°F.
10-30 CHEVROLET TRUCK SERVICE MANUAL