4-12 TIRE MAINTENANCE
4-12.1
Tire Inflation
. Tire inflation will cause
tire to ground contact characteristics as
shown in
Figure 4-20
. Tire inflation should
be checked daily while the tire is cold, and
during road stops. Checking the tire pres-
sures while tires are hot will give a faulty in-
creased pressure reading. Adjusting tire air
pressure to the specified amount while tires
are hot will produce improper tire to road
contact and thus abnormal wear. Do not ex-
ceed cold inflation pressure listed on the
semitrailer VIN plate located on the front of
the trailer. Exceeding cold inflation pressure
will result in damaged tire bodies, rims, and
wheels. Replace all valve stem caps when
pressure checking/adjusting has been com-
pleted. Remove any foreign objects from be-
tween duals.
4-12.2
Tire Matching
. Both tires on the same
spindle must be the same size in order to
properly distribute the load and braking forces
between them. The tire must be mounted on a
rim and properly inflated before measuring. If
there is an allowable difference in size the
smaller tire should be mounted to the inside
position of the duals.
a. Tape Measuring Method
: Measure around
each tire on the tread surface. A maximum
difference of 3/4" is allowed between the two
mating tires of a dual
(See Figure 4-21).
b. Straight Edge or String Method
: (This
method cannot be used if tire and wheel as-
semblies are not mounted on the axle.) Jack
trailer up until the wheels are off of the
ground. Hold a straight edge against the tires
of both ends of an axle. A gap at one tire indi-
cates a smaller tire. A maximum of 1/8" gap is
allowed
(See Figure 4-22)
.
4-29
Figure 4-20 Tire Inflation Examples
Figure 4-21 Measuring Tape Method
Figure 4-22 Straight Edge Method
Summary of Contents for 325C
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Page 44: ...4 8 Figure 4 3 Models 325 326 327 329C Wiring Diagram...
Page 54: ...4 18 Figure 4 13 Checking Axle Alignment Figure 4 14 Examples of Camber...
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