Leaky tire seals

I have a 2008 RAV-4 with leaky tires. The tires will slowly deflate from 35-20 psi over the period of a week or so. I have checked for nails without finding any. In the past we have taken them into a tire store and had them pulled to check for nails without ever finding anything. They usually reset the tires and tell us the seal between the wheel and tire was bad and they put some stuff on it and send us away. This will work for about a month and then it starts happening again.

We live on the end of a 1/2 mile dirt road. Is it possible that the dust that is kicked up by the car on the dirt road gets in the seal and degrades it? If so is there any “magic” solution you have run across or do I just stop at the gas station with free air every couple of days to top them off. Also why would our other car not be affected. I am assuming the RAV4 has good wheels or the tire place would be all over selling us some new ones.


If you have alloy wheels…they have a problem with small pinholes that leak air sometimes. A good tire shop can seal them for you. You can also have them put the wheels in a water tank and spot the leaks more easily.

Did the shop check the air valves? Malfunctioning air valves can do this. Usually it would be just one valve, but who knows? I would expect the shop to have checked this, but you never know.

How old are these tires?

Check the date code on the tires. Tires that are overly old could cause this problem.

Tires manufactured since 2000, there is a 4 digit code. eg “5107” indicated the date of 51st week of 2007

Tires manufactured before 2000, there is a 3 digit code. eg “408” indicated the date of 40th week of 1998 (0r 1988 or 1978)

“Did the shop check the air valves?”

+1 to jtsanders’ question.

Several years ago, Dill recalled millions of tire valve stems that had been manufactured for them in China. The known defective items were manufactured in 2006, so if the OP bought replacement tires a couple of years after buying this 2008 Rav, it is entirely possible that some of those defective items were still in the supply stream. Or, it is even possible that a new batch of defective Chinese-made parts were shipped to The US subsequently.

As Missileman stated, dunking the tires in a tank of water is necessary at this point in order to get to the source of the air leaks.

Anyway…take a look at this related article from Popular Mechanics:

If the tires are leaking down to 20 psi in a week the leaks should be easy to find. If the tire shop has been applying bead sealer to the beads without cleaning the corrosion from the wheel some effort may be necessary to clean the bead sealer from the tires and wheels, then properly clean the corrosion from the wheels.

This vehicle has tire pressure sensors, it is doubtful that they were replaced with substandard rubber valve stems.

Thank you for all the information. The tires are newish. When I bought the car in 2012 they were in bad shape so I had new ones put on at a tire shop that has always been honest and helpful in my experience. The valve stems are metal and seem to be in good shape.
I never knew the alloy wheels could leak through pin holes. I have s few days off later this week maybe I will inflate the and then dunk them in the sheep trough and see what happens.

What brand and model tires?

Check the manufacture date code on the sidewalls of the tires. There is a 3 or 4 digit number on the tires. it usually is preceeded by some letters. The following link tells you how to interpret the number.

Sometimes tires you buy have been sitting at the dealers for years…


Onboard Tire Pressure Monitor Transmitter/Valve Stems Have O-rings Or Seals Where They Go Through The Rims.

Kits are available to reseal these units and this often done at the time new tires are installed.

I doubt that’s the culprit, but I would dunk tank the tires and check the stems. I don’t know if your valve stems were resealed when the tires were installed.

They are Aspen touring from big o. I think the number is 1311. I am not sure about however but it is the only number I found that seems to fit the scheme described by Bill Russell

It’s most likely bead leaks caused by corrosion at the tire bead. When the new tires were installed the beads were probably not wire brushed and bead sealant was not used. I would do a leak test in a water bath and confirm that the beads are leaking. The fix is easy. Bust the tires off the rims, wire brush the beads on the wheels to remove corrosion, apply bead sealant to the beads of the tires, and reinstall the tires.

Yep to all the above. I’ve had rust on steel wheels cause leaks, valve stems, valve cores, and even had a trailer tire with a pin hole leak brand new. Tank of water (kids pool), air compressor, and lots of time looking for little bubbles can reveal the truth. Sometimes the tire shops just don’t spend the necessary time looking.

I’ve Found Bead Leaks With Tires On A Parked Car Just By Spraying Windex And Looking For Inflating Bubbles.

The fact that when the OP has had the beads resealed there is a marked, although temporary, improvement tells me we can rule out valve problems or porous alloy wheels. It has to be a bead to rim seal problem.

If the weather in your area permits, get a child’s plastic pool, fill it with water, and put the wheels in one by one. Sit back, sip on some iced tea, and watch for the bubble streams.

“They are Aspen touring from big o. I think the number is 1311. I am not sure about however but it is the only number I found that seems to fit the scheme described by Bill Russell”

That does seem like the date of Mfg. Those four digits should end a series of alpha/numeric digits that begin with DOT (for Department of Transportation). It’s referred to as the tire’s "dot number."

Sometimes alloy wheels will present with micro cracks that allow air to escape. Sometimes the tire valve is to blame. More often than not the bead area of an alloy wheel will corrode or “Bloom” as aluminum tends to do and will allow air to get out. Very common.

Get yourself a kiddie pool or big ole round wash tub…something big enough to submerge completely the wheel and tire and watch the bubble show… will tell you all you need to know…and its Scientifical!

You can also use Tire SLIME…that stuff works good in an emergency but I hate to use it as it is a friggin mess and often affects wheel balance…naturally. But it does find the leaks.


Concur with posts above to try to find where they are leaking first, before attempting any fixes. Any leak will definitely show up if the tire is completely under water. It will be easier to identify the source probably if the tire is laid horizontally under water, like in a toddler’s plastic swimming pool. Lay it on one side, then the other. If these are other than OEM wheels, e.g. any type of special performance wheel, that would be my first suspicion.