Tires leaking air

I have a 03 Lexus GS 300,we bought it new. I have a problem

with air leaking out of the tires. The car is on it’s 3rd set of tires, on the second set right before I replaced them on 2 occasions, the right rear tire went completely flat when I hadn’t driven it over the weekend. I told the tire guy this, & he said , it could be rusty around the rim. So, when they replaced the tires, they sanded around the rims. It’s been 6 months & I’m having the same problem of slow leaking. I’ve heard instead of just using sand paper & only scuffing them, you should use a grinder to make sure you do not have any corrision on the wheel, and then put a sealer over that. My husband thinks it’s the brand of tires that were put on. They are SUMITOMO brand, a HTR T4 , he always thinks you have to put the same tires on the factory had, I know as long as you go by the manufactory recommendations,like height & width, you could have any brand of tire.The tire guy said, if that didn’t solve the problem maybe we should get new wheels, he has seen this happen before with Lexus’s. (think he just wants to sell wheels)? Have you ever heard of Lexus having this problem? So,is it the corrotions on the rims, or the brand of tires? The Wheels are not bent or curbed. I’m tired of checking & putting in air, (I know we should check our air in tires every season, I do ) but not every couple of weeks. Thanks Tom & Ray, I’m sure I will enjoy your answers. The first thing I do every Saturday when I get the paper is read your article, love yur new show. Terri

Actually you should check the air in your tyres about every month. In any case, are the wheels steel or the fancy alloy wheels. If they are the fancy alloy wheels that could be the problem. Far too many of the develop leaks. You can buy a set of good old steel wheels and some nice cheap wheel covers, for for less than new alloy wheels.

Most likely it is as you say, corrosion at the bead sealing area.Find a tire specialist (not necessiarly the cheapest) tell him you are having problems with air loss,ask if you give him the job of dismounting your tires and performing any work required to get a good seal will he guarantee that the tire will not loose any more air than the design allows.Then if you continue to loose air you have recourse.Eliminating air loss is not that tough a job.

On an '03 Lexus I presume that you have alloy wheels, not steel wheels with hubcaps, right?

Alloy wheels can be porous and leak air, or they can be cracked (not good).

Don’t use a grinder on the edge of your wheel. Fine sandpaper or steel wool will do it.

Porus alloy wheels can be easily sealed while the tires are off by simply painting the inside surfaces with a waterproof paint.

Make sure it is not the valves. Remove the valve cap and put some spit or soapy water in the end of the valve and watch it for a few seconds. If it bubbles, the valve is leaking. If you have valve stems that screw to the wheel, put spit or soapy water all around the stem/wheel interface.

Thanks for the help, Yes these are the wheels that came on the car when we bought it ,they are aluminum alloy wheels,So the sandpaper or like you said, steel wool would also work,& waterproof paint to help the leaks. Great. I will check the valves, but they were also replaced when I got the tires,but I guess anything is possible. Thanks, I’ll go out & check.

Actually, the sanding or grinding is going to make the problem worse.

Alloy wheels have a clear coat that seals the pores of the alloy. If you use any sort of abrasive on the wheel, you remove the clear coat and exposed the alloy (with the pores).

CapriRacer, What do you suggest?

Capri - If the bead is already corroded (common in areas with rough winters and road salt) then the bead area must be sanded or wire brushed and coated with bead sealant. Sad to say I spent many hours going back and forth to the discount tire place trying to find my “leak” until I went to a real tire place that finally fixed it. Now I just avoid alloy wheels when I can since steel wheels are cheaper and have fewer problems sealing at the bead.

You could try a clear spray lacquer on the mating surface of the wheel.

Take your fastest leaking wheel off of the car and immerse it in water to see where it is leaking before you do anything else. Use a good light and look closely and patiently. Even an extremely slow leak can be found this way. A very slow leak will not cause a stream of bubbles to appear but will form a bubble that will form again if you wipe it away. If you have no suitable tank, a child’s wading pool can work.

Before going to the trouble of immersing it, just lay it flat and spray some soapy water around the bead and valve areas. Chances are you’ll see the leak right away.

Three sets of tires . . . they all leaked at one time? Gotta be the wheels. I can’t see ALL of the wheels having the same defect, but that’s possible. How often do you add air? I’d get another wheel/rim from Lexus if this is a wheel problem, ask them if it’s a manufacturing defect. Another option (Boy is this gonna draw fire!) . . . a can of “Stop-Leak” in the leaking wheel/tire. Rocketman

Ready, aim…yes, stop leak might work, but doesn’t that spread around the inside of the tire? Might be hard to stop a leak caused by a porous rim(s).

Hey Tex! I’ve used it to fix leaky rims . . . shake the can hard, shoot it in, and then drive the car to spin it around the entire inside of the wheel/tire. Only problem that I’ve had was it gunks up the air valve, sometimes hardens around the bead, too. Rocketman

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