Slow Leaking Tire

[curiousB]

I've had a slow leaking tire for a couple months. Its driving me nuts. Every 5-6 days the tire warning indicator comes on and sure enough the same tire is down to around 20psi.

I took it back to tire place and they removed and remounted tire after they claimed to see a bead leak in the dunk tank. They used some gunk on the bead to seal it and it worked fine for almost 2 weeks. Today warning came back on.

Last time there the tech said there was some corrosion on the wheel where the bead meets.

Have others heard of aluminum wheels corroding such that a good seal is no longer possible? Also how does salty water get into the bead when the tire is 20-32 psi this any leak would be expelling air, not leaking in salty water.

It all seems strange to me.

[SRK]

Up here in Canada with lots of road salt it is very common for the salt to wick in under the bead, and lift the powder coating off. A white aluminum oxide is formed, and air will pass through it, giving the slow leak. The wheel rim will have to be wire wheeled, or scrubbed, to remove the damaged powder coating, and then painted to prevent it's return for a while. I just use silver spray paint on alloy and steel wheels. I've repaired lots of them that way.

The black goo the tire shops use will not seal the layer of corrosion, so that's why the corroded area has to be abraded with something to remove it first. The bare aluminum is sealed with the paint, and the tire re-mounted normally.

Done carefully the spray paint is not noticeable after the tire is mounted.

I also use a lacquer thinner on a rag to clean the tire bead surface where it meets the wheel, so it conforms well.

Hopefully the valve stem was also replaced - if not it should be. Cheap.

[Don33]

I have a 2002 LS and have had the same problem several times. I am told that the wheels from 01-04 tended to corrode. The chrome plating also tends to peel off. The tire shop told me that the only solution, if you intend to keep the wheels, is to remove the tires and carefully clean the insides of the rims. I have had some luck with deflating the tire and pushing the bead down while using a strong water spray. This lasts for a year or so. I'm installing new wheels next week as a permanent repair. Good luck.

[landar]

Curious, I follow your logic on the air pressure expelling the salty water...however, it necessarily takes a leak to cause the air pressure within to expel and by then, well, you have a slow leak. Exactly your wheel's condition. The expelling air may work to decrease further corrosion but, by definition, the leak is already there. I think the salty brine sets in the groove and "works" on the sealed area undisturbed until driving pressures, like hitting a pot hole or tight cornering, slightly alter the seating of the bead causing the leak to show up.

This may sound a bit crazy but every fall just before the snow flies, I "grease" my cars vulnerable areas. I literally use bearing grease and smear a thin layer around the inside of the fender sheet metal and the bead area of the tires rim. While a little messy, I feel it provides some protection throughout the winter salty months.