GMC 1986 P-Truck Service Manual page 365

3E-8 WHEELS AND TIRES
Tube Type Tires
Important
• Only use rims approved for radial tire usage by
the rim manufacturer.
1. Clean the rim parts.
• Remove all rust and other foreign material.
• Make sure the rim parts match and are not
sprung or broken.
2. Lubricate the tire beads, the portion of the tube
between the beads, and the flaps with an
approved rubber lubricant.
• Radial tubes are identifiable by the letter
" R" in the size designation. A red band in
the valve stem and an " R" in the flap size
designation also identify radial parts.
NOTICE: Do not
lubricants—this could cause the tire to slip on
the wheel.
3. Inflate to operating pressure, deflate completely,
and reinflate to operating pressure.
• Allows the tube, flap, and tire to fit together
properly.
4. Check the bead seating.
• Visually check the slot and side ring gap (on
two piece rims) to make sure the bead is
seated.
5. Check the spacing between the rim flange and
one of the three lower sidewall rim line rings while
the tire is laying flat to verify bead seating.
• Measurements must be taken each 90
degrees around the circumference of the
rim flange.
• If the spacing is uneven around the bead
from side to side, repeat steps 1 through 3,
then recheck.
Installing Synthetic Tubes
NOTICE: When the tube and the flap are not
properly lubricated, and mounted, they will
stretch thin in the tire bead and rim region.
This will cause premature wear.
1. Clean the inside of the casing.
2. Insert the tube in the tire and inflate until it is
nearly rounded out.
3. Inspect the rim for rust scale and bent flanges.
• Clean rust scale and straighten the flanges
where necessary.
4. Apply a solution of neutral vegetable oil soap to
the inside and outside of the tire beads, and also
the rim side of the tube.
• Use a brush or a cloth swab.
use silic o n e base
• Do not allow the soap solution to run down
into the tire.
5. Follow the standard procedure when mounting
the tube and tire on a drop center rim. Be sure
the tire is centered on the rim so the beads are
out of the rim well before inflating. Do not allow
the tire to hang loosely on the wheel while
inflating.
. Center the valve and pull it firmly against the rim.
6
Hold in this position and inflate until the tire
beads are firmly seated on the rim against the
flanges.
7. Remove the valve core to completely deflate the
tire.
. Reinflate the tire to the recommended pressure.
8
• Refer to " Tire Load Limits And Inflation
Pressure" at the end of this section.
Tubeless Tires
Important
• Only use rims approved for radial tire usage by
the rim manufacturer.
1. Clean the rim.
• Remove all rust and other foreign material.
2. Lubricate tire beads and rim bead seats with an
approved rubber lubricant.
NOTICE: Do not
lubricants—this could cause the tire to slip on
the wheel.
3. Inflate the tire to operating pressure.
• Due to the construction of radial truck tires,
particularly in the lower sidewall and bead
area, it may be difficult to get the tire to take
air.
• An inflation aid may be necessary to help
seat the bead of tubeless radial tires. Two
types of inflation aids are commercially
a v a ila b le — m etal
compressed air to seat beads, and rubber
rings which seal between the tire bead and
rim bead seat allowing the bead to move out
and seat. Lubrication is necessary with both
aids.
4. Check the spacing between the rim flange and
one of the three lower sidewall rim line rings while
the tire is laying flat to verify bead seating.
• Measurements must be taken each 90
degrees around the circumference of the
rim flange.
• If the spacing is uneven around the bead
from side to side, repeat steps 1 through 3,
then recheck.
use silic o n e base
rin g s w h ich use