After the tyre pressure monitoring system (TPMS) in my European car prompted me to “Check tyres!”, I did so at a service station nearby. The front right tyre’s air pressure was about 100 kPa lower than the other three, properly inflated tyres.
I drove my car to the workshop, where the mechanic jacked up the car and found a nail embedded in the front right tyre. He then proceeded to patch the tyre, pump all four tyres to the recommended pressure and reset the TPMS.
How is the tyre patching done? And how safe is it to continue driving on the patched tyre? Can the same tyre be patched more than once or in several different spots?
Most tyre shops will remove the tyre from the wheel to repair any puncture hole. They will then clean the punctured area on the inside of the tyre by rubbing down with mild abrasive, ensuring there is no part of the foreign object still embedded in the rubber. The actual patching involves the fixing of a vulcanised adhesive “plaster” over the cleaned area of the puncture hole.
This method of patching punctures is safe enough for use till the end of the tyre’s life. There is no harm doing more than one patch on a tyre.
In any case, unless you frequently drive on roads littered with debris, you rarely have a tyre going through three punctures or more in its lifetime.
Some tyre shops still use the old method of inserting a solid rubber stud into the hole pierced by the nail.
It is easy, does not require the tyre to be removed from the rim, and effective in plugging the hole left by the nail or a sharp object. This quick fix is also available off the shelf for the DIY motorist.
Although fussy car owners might refuse to allow this method of repair, it used to be the only way to fix a puncture, and nothing adverse happened due to this plug-in type of puncture remedy. Plugging more than one puncture in this manner will not reduce the tyre’s lifespan.