Stock rims losing air

We are a Toyota family. We drive other things, but mostly Toyotas.

My son has an '07 4Runner that has had a tire slowly losing air and needing to be aired up, for years. Recently he bought new tires and now all of them are needing to be aired up weekly. The place he bought the tires from has checked them, and so has another shop with a good reputation, and they say it is the rims. Neither place sells wheels.

I've heard of magnesium rims leaking through porous metal.

Is there some kind of treatment that can be applied to the wheels to stop air leaking? Looking for some kind of fix to avoid replacing the wheels.

EDIT: I'm skeptical of the diagnosis myself except that we've already exhausted all of the typical issues which is what all of the suggestions so far cover. At this point I'm asking if anyone knows of any kind of treatment to seal porous wheels. It's something to try at this point and I'm interested in seeing if it could be what they are saying.
So I'm NOT asking for a diagnosis of things already investigated (valve stems, TPMS, bead leaks). Does anyone have a suggestion on sealing the wheels themselves?

EDIT: And yes, we've considered replacing the wheels. Looking for an answer to the question asked first.

 

I can't help much with the wheel problem, but I like your tagline.

The only 2 things I am aware of, are to wire wheel the bead area to remove rust or corrosion. And hope that it worked.

 

Check the valves and stems with soapy water. You can try something like slime. However, tire shops may refuse to patch a flat that have been slimed.

 

The valves and stems have been checked multiple times. But thanks.

 

When placed in a tub of water the bubbles will show the leak point(s).

Bead area is #1 candidate. In addition to cleaning as well as possible I have also used a bead sealer in the past. It worked well on my race tires (hint, not on the Tacoma)

Any tire shop worth your time should have a test tub like this https://tiresupplynetwork.com/products/large-tire-test-tank?variant=7309150388271

 

See it all the time.
More than likely beads are corroded. Needs some sanding disk work with someone that knows what they are doing and looking for. Easy to do otherwise. If the beads are leaking I’m sure the stems are not far behind. Do it all and be done with it.

 

As said, the problem has been thoroughly investigated and the rims found to be leaking.

We are looking for a sealant for the metal, porous rims.

 

You have wheels from the 60s? Last mags I recall were Keystones on a buddies 65 Mustang.

Pictures of wheels please. For posterity.

 

Okay... they look like magnesium to me. What are they? Alloy? Please inform me of the material used so I can be more accurate.

 

Don’t need it until you clean and inspect

 

I’ve never heard of anything like this and actually seems a little hard to believe but I guess it could happen, it seems even stranger that it’s all 4 tires. Like others I would think bead or valve stems but I guess it could be the wheels

 

As said... already thoroughly investigated and now diagnosed as porous rims. Beads cleaned and refinished.

 

If they are Toyota wheels they are either steel or an alloy. Neither of which are known to leak air due to porosity. On Toyotas or any other marquee I'm aware of.

It's why everyone keeps pointing to the beads (2 per wheel) or valve stems. If the stems are new with the new tires, they should be fine. If they are older TPMS stems and did not get a reseal kit, they are suspect too.

 

Okay... I appreciate all of your suggestions.

I'm skeptical of the diagnosis myself except that we've already exhausted all of the typical issues which is what all of the suggestions so far cover. At this point I'm asking if anyone knows of any kind of treatment to seal porous wheels. I'm NOT asking for a diagnosis of things already investigated.

Does anyone have a suggestion on sealing the wheels themselves?

 

If your aluminum or steel wheels are themselves leaking, then you have problems that probably shouldn’t be hidden with a sealant.

I would get them dunked to pinpoint the leak and go from there.

 

Leaks are too slow to see in a dip tank.

 

Ford trucks/SUV's from the 90's absolutely had porous rim leakage. Nissan totally replaced rims on their Xterra in the early 2000's because they replaced ours.

 

Maybe I missed that you cleaned them. Bead sealer does help some….

 

If the problem has been thoroughly investigated and the tech has done everything they can. Than your pretty much shit out of luck. Your cheapest solution would be to buy someone take of wheels and be done with it.

 

Seems like a can of worms to chase down and try and seal the leaks. I'd replace the wheels.