Dear Ole Mechanic;Lawnmower Tire

I know now that I goofed up.  I should have aired up the tire on my riding mower when I first noticed that it was going flat, but I never got around to it.  It went completely flat, and the bead of the tire became unseated from the steel rim.  When I tried to air it up yesterday, the air just escaped around the bead.

Now what do I do?  Is there a simple way to get air in the tire so that the bead will seat, or do I need to take the wheel assembly to town and pay someone to get it seated so it will stay on?   Thanks.

Feeling Let Down

Dear Let Down;

Since the tire went flat, don’t you think it might have a hole in it?  While it is already down, now would be a good time to check it or have it checked for a leak.

OK, so it went down slowly, and you only need to put air in it once in a blue moon.  Yes, there are a couple of tricks that can be used to seat the bead.  Both involve getting the tire up in the air so there is no weight on it, but the tire doesn't need to be removed from the mower.  If you have some time, then just leave the tire up in the air for a day or two or three.  You might even poke and squeeze the tire back to its normal round shape.  After a few days, try adding air as you thump on the tread of the tire with your fist or a small mallet. 

Didn’t seat?  OK, the air must make its way past the valve core in the valve stem.  That restricts the flow of air and you cannot get a good blast of air to get the bead to seat.  Try removing the valve core and then repeat by adding air while you thump on the tread of the tire.  Sometimes removing the valve core allows enough more volume of air in and the bead will seat.  Once seated and aired up, the bead will usually stay seated while you replace the valve core.

Still didn’t seat?  It is time to get serious.  Get enough rope so that you can tie it in a loose loop around the tread of the tire.  Get a bar, a big screwdriver, or a stout stick.  Put it between the tire and the rope.  Start twisting the rope like you were tightening a tourniquet.  The object is to squeeze the center of the tread in towards the rim.  This will force the beads of the tire out towards the rim and--hopefully--allow the bead to seat when you give it a good long blast of air through the valve stem.  I hope you didn’t reinstall the valve core, as an unrestricted blast of air helps also.  I have had to try the tourniquet procedure two or three times to get the rope just, but this method has never failed for me.  However, if it still didn’t seat, it is time to remove the wheel assembly and get some professional help. 

Most tire shops have two different pieces of equipment to do the job.  One looks like a braded rope that has a valve stem sticking out of it.  It slips over the tire like the rope loop and, as it is aired up, it squeezes the tire like the rope tourniquet I mentioned earlier.  The other piece of equipment is an air tank that has a large quick opening valve.  The outlet is positioned near the bead of the tire and the rim.  It gives a tremendous blast of air--so much air that the tire pops its beads back onto their seats on the rim and partially inflates the tire.

There is a method that some people have tried that I will tell you NOT to use!  It involves spraying starting fluid or some other flammable into the tire and then throwing a match at it.  More often than not the tire, explodes and usually winds up in an EMS ride to the hospital to have embedded chunks of rubber removed from various parts of your body.  That's what happens IF you survive the blast. DO NOT USE THIS METHOD to try to seat tire beads.  Get professional help as it is a lot cheaper than a hospital visit or a funeral.

Herr Professor Nuzanbolts