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In early June, I pressurized my tires to about 50 psi (max sidewall is 44). At the first gas stations I went to, the air hoses had a great deal of trouble putting air into my tires. I finally found one that worked, though.

The last two times I checked the air pressure in my tires, I had trouble again putting air in the tires (once with a bicycle pump, and just today at a gas station). I finally gave up this morning because I was actually lowering the pressure by 1 psi every time I tried pumping air into a tire.

The tires are only about 1.5 years old, and were filled with nitrogen (I think) at Costco. Is there anything about nitrogen that would cause me to have trouble putting air in my tires? I have trouble with all four tires, not just one. Is there anything else that would cause me to have problems at several different gas stations?

Like I said, a silly question, but a problem that's a bit frustrating.

There is nothing about the nitrogen that would cause your problem. It sounds more like the issue could be the valve stems. Maybe?

There is nothing about the nitrogen that would cause your problem.
What about the high pressure that is already in the tire? Could that cause problems for the air pumps at the gas stations?

No. Maybe the pump was dying at one station. But for you to have problems at numerous stations doesn't point to the pumps. The air pumps at stations also have to pump up semi's tires too, so they should have plenty of oomph for those.

Some/most gas stations limit how high their compressor can pump since they don't want you to get injured blowing your tire off . It might be set at 40/45 psi max. This would be fine for most passenger vehicles. Now 3/4 1 ton trucks take 80 psi, and big rigs take I don't know what, but probably high. Most city stations don't service big trucks,so they don't care about 80 psi pressures.

They assume folks might screw up and blow their tires off if they have 100 psi to work with.

Charlie
PS-I find it really tricky to get my bike pump "nozzles" to clamp on car tire stems.

That happens to me a lot. Most places require 50cents now though and they are usually fairly reliable.

The hose end could be worn or the pressure turned down at the gas station.

If this happens at a truckstop .... it definitely would make something else suspect.

(now that you mention it ... could the nitrates corrode the inside of the stem ??)

Someone posted in the other max sidewell thread that their big rig could be set to 70 for light loads, and up to 100+ for heavier loads.

(now that you mention it ... could the nitrates corrode the inside of the stem ??)
I don't think here are nitrates involved. Some service stations use nitrogen to fill tires because the nitrogen molecules are bigger and shouldn't leak out of tires as quickly (of course, air is 78% nitrogen, so it's not a huge difference). Nitrogen is chemically inert, so it shouldn't cause problems with the stems or tires.

Most city stations don't service big trucks,so they don't care about 80 psi pressures.


As far as I know the trucks just connect their own tool to the brake air tank/compressor :)

Try going to a farm store or one that services tractors and such. A lot of tire places have high pressure air lines. BUT once you find a free high pressure air line, remember where it is! I finally found one for free that will do over 80 psi.

My sidewall is rated 35 psi max (175/70/13) and mine are at 40 hot right now. I will have to check them cold and make sure they are at 40 psi still. I gave in and bought a 10 gal air compressor for home. I live on gravel roads, so flat tires are common out here.

i found a shell staion that has free air, with a fairly high PSI output. wasnt payin attention n it pumped it probably round 55-60 psi(tire gauge only went to 50...) before i took it off. yesturday tho, it gave me some problems, seemed my tire was letting out more air than the compressor was putting in. confused, i checked the tire's psi again, 5 lbs lower. then i saw a valve on the wall, where the hose lead to, n it was closed. opened it up, n pumped up my tires! maybe that was ur problem, maybe thay turned the valves off?

PS-I find it really tricky to get my bike pump "nozzles" to clamp on car tire stems.

There are two types of valve stems:

- Schraeder, which are larger diameter and are used on cars and some bicycles

- Presta, which are smaller and have a knurled metal tip which you have to unscrew to get air in - these are used on high pressure tubes for racing bikes

When buying a pump for your car tires, be sure to get one that works with Schraeder valve stems. Some bicycle hand pumps are made to accept both; I got one of these because I have one bicycle with the high pressure tires.

I can't complain, I've got my own personal 150gal compressor that runs at around 125psi inside the tank.

I don't think here are nitrates involved. Some service stations use nitrogen to fill tires because the nitrogen molecules are bigger and shouldn't leak out of tires as quickly (of course, air is 78% nitrogen, so it's not a huge difference). Nitrogen is chemically inert, so it shouldn't cause problems with the stems or tires.


May be you should buy your own compressor and use it to pump your tires. Most gas stations are good up to 45 psi. Anything beyond that you are blowing air into the compressor.

Note: Inflation using nitrogen is a silly sales gimmic. I find it hard to believe that someone can get sucked into it. (I rest my case!)

Note: Inflation using nitrogen is a silly sales gimmic. I find it hard to believe that someone can get sucked into it. (I rest my case!)
Some places, like Costco I think, use nitrogen as a matter of course. It's not necessarily something a consumer has to pay extra for, and there isn't a downside that I'm aware of.