All Four Tires Losing Air

I just picked up a 1991 Buick Regal for a good deal, but already the repair costs to get this thing up to speed are mounting :\

Right now I’m dealing with all four tires losing pressure. The 24 year old car still has its original wheels (15 inch aluminum) and I’m assuming that they are losing pressure at the seal. The tires are only about a year old and the stems look okay, so do you think I’m on the right track?

There is one strange part to all of this: The vehicle with its equipped tires is rated at 30 PSI and if I fill them to 30 they are all down about five pounds within a few hours or after a drive. However, they do not lose more than or much more than 5 PSI. The front tires lose more air and lose it faster, but the lowest I’ve seen them is 23. Is only losing a few pounds of air and not going flat evidence of a seal leak or am I in the twilight zone?

Cheers.

It is very possible that those alloy wheels have become “porous” over the passage of over 2 decades. Why not visit an auto recycler (junk yard), and buy a set of 4 steel wheels to mount the tires on? More than likely, this would resolve your problem at a relatively low cost.

If you don’t like the appearance of the “steelies”, you could buy some cheap wheel covers at Pep Boys.

I think VDCDriver is right. All 4 leaking is highly unusual. I suspect that someone used a solvent on the wheels and stripped off the clearcoat.

So if the tires are losing 5 psi in a few hours, you ought to be able to see that. Either spray the whole tire and wheel assembly with soapy water or dunk one. Look for bubbles. Patience is a virtue.

This is another vote for @VDCdriver since I went through this same problem a couple of years ago. I had a tire shop seal the wheels internally which worked fairly well but they still leaked off a few pounds in a couple of months.

Also remove the valve caps and spray soapy water into the valves to check for leaks.

The only way I can see what you’re describing happening is that you drive home, find the tires at 25 psi, fill to 30, and and a few hours later (or next morning) they’re at 25 because they were warm when you filled them. Try filling all to 35 psi in the morning and see what happens.

I also vote for checking with soapy water. With a leak that big, you’ll find it easily.

The local scrap yard has 15 inch steel wheels listed on their website at $34 (lugs included). This seems odd, as the local big tire store has new steel wheels for $39.99. So, I’m looking at about $50 plus installation for steels including wheel covers.

The big tire store also has new aftermarket aluminum wheels for $70 (salesman said he could probably knock a few bucks off if I bought them today, I assume I can still haggle for that). The aluminums aren’t gaudy and they would surely look better, but any performance or other reasons to opt for spending the additional $20 for the aluminum wheels?

On a 20+ year old car, I would suggest going with the cheapest possible solution, ergo a set of steelies.

The caveat is that this was a friend’s family car. It spent its first 15 years in Florida, garage parked. The last 8 it has been a mechanics “back up” car that he used in between car purchases and for long trips. It only has 113,000 miles with a GM 3800 v6 and everything aside from the r12 AC is in full original working order. I’m planning on getting another 100k out of this thing, though old transmissions have bit me in the behind before.

Do NOT get the aluminum aftermarket rims from the big tire store

They are undoubtedly Chinese, and are part of a limited production run

If you buy them and bend one going over a pothole a few months/years later . . . the tire store will no longer carry them. And neither will anybody else. Then you once again will have a choice to make

Even if you buy the junkyard stamped steel rims, test fit one before buying. Even though the diameter is correct, the offset and width may not. You must make sure they don’t interfere with the brake calipers.

Before buying any new wheels I would have a tire shop bust the tires off the current rims, wire brush the beads on the rims, apply bead sealer and remount the tires. 9 out of 10 times alloy rims will stop leaking after this treatment.

I still recommend the first step being finding where the leaks are. It might just be something simple.