Thermostatic Air Cleaner Check; Drivebelt Check, Adjustment And Replacement - Jeep cherokee 1989 Owner's Manual

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25

Thermostatic air cleaner check

Refer to itlustrations 25.3a and 25.3b
1 Some engines are equipped with a thermostatically controlled air
cleaner which draws air to the carburetor from different locations, de-
pending on engine temperature.
2 This is a visual check. If access is limited, a small mirror may have
to be used.
Locate the air valve inside the air cleaner assembly. It's inside the
3
long snorkel of the air cleaner housing (see illustrations).
4 If there is a flexible air duct attached to the end of the snorkel,
leading to an area behind the grille, disconnect it at the snorkel. This
will enable you to look through the end of the snorkel and see the air
valve inside.
5 The check should be done when the engine is cold. Start the en-
gine and look through the snorkel at the air valve, which should move
to a closed position. With the valve closed, air cannot enter through
the end of the snorkel, but instead enters the air cleaner through the
flexible duct attached to the exhaust manifold and the heat stove pas-
sage.
6 As the engine warms up to operating temperature, the air valve
should open to allow air through the snorkel end. Depending on out-
side temperature, this may take 10-to-15 minutes. To speed up this
check, you can reconnect the snorkel air duct, drive the vehicle until it
reaches normal operating temperature, then check to see if the air
valve is completely open.
7 If the thermostatically controlled air cleaner isn't operating prop-
erly, see Chapter 6 for more information.
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valve shown open) when the engine is cold, the air valve (I) should close off the
snorkel end (2), allowing warm air to flow through the flexible duct (3), which is
attached to the exhaust manifold and heat stove passage -when the engine is at
normal operating temperature, the air valve should be open, allowing cool air to flow
GLAZED
I
26.3 Check the V-belt for signs of wear like these
worn, replace it
The Motor Manual Guy
Chapter 1 Tune-up and routine maintenance
through the snorkel end (2)
GREASE
ALWAYS CHECK
the underside
of the belt.
if it looks
26

Drivebelt check, adjustment and replacement

Refer to illustrations 26.3, 26.4a, 26.4b, 26.5a, 26.56, 26.12a and
The drivebelts, or V-belts as they are often called, are located at
1
the front of the engine and play an important role in the overall opera-
tion of the engine and accessories. Due to their function and material
makeup, the belts are prone to failure after a period of time and should
be inspected and adjusted periodically to prevent major engine dam-
age.
2 The number of belts used on a particular vehicle depends on the
accessories installed. Drivebelts are used to turn the alternator, power
steering pump, water pump and air conditioning compressor. Depend-
ing on the pulley arrangement, more than one of these components
may be driven by a single belt. Later models are equipped with one
serpentine drivebelt that runs all engine accessories.
3 With the engine off, locate the drivebelts at the front of the engine.
Using your fingers (and a flashlight, if necessary), move along the belts
checking for cracks and separation of the belt plies. Also check for
fraying and glazing, which gives the belt a shiny appearance (see il-
lustration). Both sides of each belt should be inspected, which means
you will have to twist the belt to check the underside. Check the pul-
leys for nicks, cracks, distortion and corrosion.
4 The tension of each V-belt is checked by pushing on it at a dis-
tance halfway between the pulleys. Push firmly and see how much the
belt moves (deflects) (see illustration). A rule of thumb is that if the
distance from pulley center-to-pulley center is between 7 and 11
inches, the belt should deflect 1/4-inch. If the belt travels between pul-
On inline six-cylinder engines, the
thermostatic air cleaner is located
towards the front of the driver's side of the
engine compartment
mirror in front of the radiator support to
STRAIGHT
. ..
MAKE SURE RULER IS
PERPENDICULAR TO STRAIGHT EDGE
and ruler
you must put a
view the air valve
BELT
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