Tire repairs can be made in many different ways. Puncture hole up to 1/4in i.e. 6.3mm in diameter can be plugged and patched from the inside of the tire. Small nail hole tire punctures can be repaired quickly from outside in by inserting a plug, shooting a rubber rivet saturated with vulcanized cement. However, those are emergency only methods. A permanent inside-out repair must be made as soon as possible puncture holes in radial tires are repairable only in the tread area.
Permanent tire repair method includes head tire plug cold patch, hot patch, and chemically or electrically vulcanized patch. Plug and rivets are designed to stretch for easy installation into the punctured hole to help the return to full molded size.
Moisture plugs and rivets can be installed by using an inserting needle, guide, and plunger tool, or a gun, when installed, the plug top or rivet is cut off 1/16in above the tire tread.
Patches are cemented in place over the punctured hold by creating a bond between the underside of the patch and the inner wall of the tire. Installing filter rubber on the tire repaired punctured hole before the patch is installed is recommended by some repair kit manufacturers. Others have a soft laminated patch having a layer of soft rubber that flows into the puncture hole while the car is being driven. The cold patch and the self-vulcanizing patch are installed in the same way. The puncture hole is probed with a tool dipped in vulcanizing cement. An area twice the size of the patch is buffed and cleaned with solvent.
Filter rubber is installed, during the process; a uniform coat of vulcanizing cement is applied to the buffed area and allowed to dry. The path is installed over the puncture hole stitching. The assembly is centered over the punctured hole and a U-clamp is locked in place over it. Secondary and ground wires are attached to a transformer, patch heating element and then its clamp. For the electrical method, the transformer power lead is plugged into a 120 volts receptacle where the electric vulcanization takes place.
RETREADING AND RECAPPING OF CAR TIRES
The life of a tire can be materially extended by either recapping or retreading.
Recapping involves adding a top strip known as camelback of synthetic. While Retreading means adding full-width new rubber to the worn tire. The terms are used rather loosely and interchangeably in the tire industry but a retread is bonded to the tire from one shoulder to the other.
The experience of truck fleet operators shows that retreading tire life is increased from 75 to 100 percent. In general, a truck tire is in need of retreading after 35,00 to 70,000 mile of service, radial tires are said to add 12 percent more mileage to these figures. Tires with weak spots should not retread. Most operators retread before the tread design is worn smooth.
HOW TO CHECK TIRE VALVES FOR LEAKAGE
Basically, tire valves are the first thing to check whenever leakage is detected from any car tire. The valve and its surrounding will be checked for any sign of leakage. The checks open under pressure and close when the pressure is removed with the aid of liquid like water aimed at creating bubbles at the leaking locations or points.
In the process, the gasket passed against the end of the valve stem that seals the air in the tire. The careless practice of operating tires without the valve cap should not be followed. Without the valve cap in place, there will be a slow seepage of air from the tire. It is necessary to install a new tire valve assembly. This is easily accomplished by means of a special lever type tool.
