Pontiac FIREBIRD 1972 Service Manual page 1246

WHEELS AND TIRES 10-9
CAUTION:
During the entire operation of
breaking beads away from rim and removing
tire from rim, special care should
be
taken not
to damage the tire beads.
3. Use standard tire-changing machine to remove tire.
PUNCTURE REPAIRS
Puncture repairs may be quickly and permanently per-
formed, using one of several kits available through tire
manufacturer's dealer outlets. "Hot patch" types are
recommended for puncture repairs.
WHEEL LEAKS
Examine rim flanges for sharp dents. Any dent visible to
the eye should be straightened. NEVER USE HEAT
when straightening a wheel.
CAUTION: Under no circumstances should
wheels be brazed, welded or peened. In the
event the wheel is severely damaged, it should
be replaced.
PREPARATION OF TlRE
Remove excess strings of rubber hanging from tire bead.
PREPARATION OF R I M
Clean rim flanges with small piece of No. 3 coarse
steel wool or emery cloth to remove all oxidized rub-
ber, soap solution or rust. If rim is badly pitted, use
file to remove and PAINT WITH PRIMER.
Straighten or replace bent or damaged rim.
MOUNTING TlRE ON WHEEL
Install new valve if valve was removed. Always install
type T.R. 413 valve or equivalent.
Apply liberal amounts of vegetable base soap solu-
tion.
NOTE:
A
non-drying type lubricant may cause
the tire to walk around the n'm in service.
Mount tire on the wheel with valve hole side up,
using the machine method.
4. Remove valve core from stem to increase flow of air.
5. With casing on the rim so that the beads are resting
uniformly on the bead ledge, quickly apply a large
volume of air. This forces the bead on the bead seat
and against the flanges where the air seal for the tire
is obtained. Inflate tire until beads are completely
forced against rim flanges.
WARNING: DO NOT STAND OVER TlRE WHEN
INFLATING. BEAD WIRE MAY BREAK WHEN
BEAD SNAPS OVER SAFETY HUMP. DO NOT
EXCEED 40 LB. AIR PRESSURE WHEN INFLAT-
ING. IF 40 LBS. PRESSURE WILL NOT SEAT
BEADS PROPERLY, DEFLATE, LUBRICATE AND
REINFLATE.
6. Once beads are seated against rim flanges, air pres-
sure can be released.
7. Install valve core and inflate to proper specifications.
8. General precautions in mounting tires:
a. Use tire mounting and dismounting machine.
b. Do not use hammer or tire irons.
c. Work over rim flange so that the section nearest
the valve stem will be applied last.
INSPECTION BEFORE BALANCING WHEELS AND
TIRES
Check and if necessary, adjust front wheel bearings
as outlined in Section 3.
Set tire pressure to cold specifications and drive car
until tires are hot.
Attach a dial indicator to the car body or stationary
support and check runout as shown in Fig. 10-1 1.
Runout measurements for the whole assembly (Fig. 10-1 1
steps 1 and 4) are the most significant.
Excessive total lateral or radial runout of wheel and tire
assemblies can sometimes be reduced within specifications
by rotating the tire on the wheel until the high spot on the
tire indexes with the low spot on the wheel. If this proce-
dure fails to bring the total radial or lateral runout within
specifications, check for damaged or improperly mounted
tire, bent or distorted wheel, and variations in tread sur-
face due to wear and correct as necessary.
BALANCE PROCEDURE
The preferred method of balancing wheels and tires is with
on-the-car type equipment; but, whether on or off car-type