Q: Are the metal air-thru valve caps as good as regular valve caps in helping to keep tires properly inflated?

A: These air-thru valve caps are used by many fleets and the people I have talked to seem to be happy with their performance. I still believe the regular metal valve cap is better, but when you use regular valve caps it takes quite a bit longer to complete an inflation check.

Q: Can I retread a truck casing that does not have a new tire DOT Code?

A: Truck casings can be retreaded even if the original new tire did not have a date code and you apply a retread DOT Code when you retread it. If the original DOT Code has been removed, it could still be retreaded, but I would not recommend it. Usually, when a new tire DOT Code has been removed, it means the tire has been adjusted with some type of flaw. If you retread a tire that has had the DOT Code removed and it is involved in an accident, you would be hard pressed to prove that the tire was not defective.

Q: We use a four-inch stone to dress up the edges of retreads or repairs. It does a really nice job, but is there any way to reduce the scoring that occurs?

A: You can reduce the speed of the stone to 1750 RPM and move the stone faster over the area that is being buffed. You can also rig up a small air line that will blow air onto the area that is being buffed as the stone makes contact with the surface.

Q: Will we use fewer rasp blades with a convex rasp hub compared to the original wide rasp hub?

A: In the checks I have made, the convex rasp hub will use fewer rasp blades mainly because using the wide rasp causes many of the blades on the outside of the hub to be thrown away at blade change time with little use. Some plants try to keep the outer blades on the wider hubs and use them on another hub, but most do not.

Q: We have an 11R22.5 casing that has the name of the manufacturer in raised letters on both sidewalls, but on one sidewall it has the name of another tire brand’s name indented into the sidewall. The indented letters are faint in some areas, but are definitely readable. How is this possible?

A: I have seen this condition only once and I believe there are two possibilities with the most likely being that this casing was touching a tire of another brand that was running against it in a dual operation. When tires in a dual assembly are mounted with the wrong dual spacing, it causes them to rub together, which is also called kissing, and if the tires are overloaded or underinflated, the condition is worse. The rubbing together of the tire sidewalls can cause the markings on one tire to be worn into the other tire. The sidewall will also generally be smooth and shinny. In rare instances a casing may develop an impression of a letter if it has been run in a full tread mold with letters in the side plate.