loosen the other bead. Once the beads are broken, the tire can be removed from the rim by standing the tire on the thread and prying the wheel out of the tire. Ensure the valve stem is not bent or damaged as the wheel is removed. To replace the tire, position the wheel, as shown in figure 3-32, view C. Lower the tire over the rim, and at the same time, make sure the valve stem is passed through the valve hole and points upward. NOTE: The  valve  stem  should  always  point  toward the removable side ring. If there is no side ring, point it toward the disc portion of the wheel. The next step is to center the side ring and force one end into position with your foot. Then the ring can be installed as shown, or the repair person can merely walk around the top of the ring and force it to slide into the locking groove. Inflating a tire mounted on a locking ring rim is dangerous. An improperly seated lock ring may blow off, causing serious injury to you or any other person in its path. A sprung ring, or one which is bent or twisted, may be difficult to install and, if used, is a safety hazard and should be replaced. Before applying air pressure to this tire, be sure that the locking ring is seated against  the  rim  of  the  wheel  through  its  entire circumference.  If  the  lock  ring  does  not  seat  properly, inflate it to 5 to 10 pounds, then tap the locking ring carefully with a mallet. NEVER STAND IN FRONT OF OR  OVER  THE  LOCKING  RING.  ADDITIONALLY, REMEMBER  TO  USE  THE  SAFETY  CAGE  FOR INFLATION. When you have to inflate a tire that is already mounted, use a snap-on chuck which is an air hose that snaps onto the valve stem. This allows you to stand to one side of the tire.  Make it a professional practice to never stand in front of a tire being inflated. Tubeless Tire Repair Some tires are tubeless. Instead of being sealed in an inner tube, the air in these tires is sealed in a space between the outer casing and the rim. Both this space and the point of contact of the tire against the rim must be airtight. The rim, on which the valve for inflating the tire is mounted, becomes a part of the air-retaining chamber. Do not tear or otherwise injure the sealing ribs. Before  replacing  a  tubeless  tire,  examine  the  rim carefully for dents, roughness, and rust; any defects may impair or break the air seal. Straighten out any dent with a hammer, and use steel wool or a wire brush to clean the bead seat area of any rust or grit. After cleaning, paint any bare metal spots where the tire bead seats to make it easier to remove the tire later. If the rim is badly damaged, replace it with a new one. The  procedure  for  repairing  a  tubeless  tire  is accomplished  by  the  following  steps: 1. Inspect the inside of the tire and remove nails or other damaging items. Then scrape the damaged area with a sharp-edged tool and buff (fig. 3-33, step 1). Be careful not to damage the liner or expose any cords. NOTE: Serious injury can result using your bare hand to free for obstructions, use a rag to feel inside the tire. 2.   Lubricate   the   hole   by   pushing   bonding compound into the hole from both sides of the tire (fig. 3-33, step 2). Also, pour bonding compound on the insertion tool and push it through the hole with a twisting motion until it can be inserted and withdrawn easily. 3. Using a plug slightly larger than the hole, place it in the eye of the hole of the insertion tool. Wet the plug with  bonding  compound.  Always  pour  it  directly  from the can so the contents in the can does not become contaminated,  as  shown  in  figure  3-33,  step  3. 4. While stretching and holding the plug with your hand, insert the plug into the hole from the inside of the tire. Stretch and hold the plug until it is forced into the hole and one end extends through it, as shown in figure 3-33,  step  4. 5. After the plug extends through the tire, remove the insertion tool and cut off the plug approximately 1/16 inch above the surface (fig. 3-33, step 5). 6.  When  using  a  cold  patch,  carefully  remove  the backing from the patch and center the base of the patch on the damaged area. Stitch the patch down firmly with the stitching tool working from the center out (fig. 3-33, step 6). 7. When using a vulcanizing hot patch, cover the area with a light coat of glue and allow it to dry. This glue normally comes with the hot patch kit. Remove the backing from the patch and center it on the damaged area. Clamp it finger tight, apply heat, allow to cure, and then cool. (fig. 3-33, step 7). NOTE:  Each  patch  or  plug  kit  should  contain specific  instructions. 3-16