Tire pressure - how odd is this? |  |  |
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| Tire pressure - how odd is this? Bobtesa - Tuesday, 16 August, 2011, at 8:35:07 pm |
Wife and I were away for 3 weeks, so I inflated the tires (as you might for winter storage) to about 42 front, 50 rear. Not that sitting idle for 3 weeks is a big deal, but what the heck. Returned yesterday and went to drive the car today. First thing - let out air to 32/37. But, before letting out the air, I checked the pressure. Three tires had lost at least 5 psi, but one (left rear) was still at 50. I check my tire pressure regularly and there aren't any slow leaks that I know of. How weird is this? Can tires loose pressure from NOT being driven? That doesn't make sense.
1999 Arctic Sivler/black/black (sold)
2008s Silver/black/black - so predictable
2011 Outback
8/24/2011 first Grandson
1999 Arctic Sivler/black/black (sold)
2008s Silver/black/black - so predictable
2011 Outback
8/24/2011 first Grandson
| It is possible. Tires benefit from being used as this helps the oils in the rubber move about... MarcW - Tuesday, 16 August, 2011, at 11:08:14 pm |
and this helps keep the tire/rubber pliable and tiny cracks/voids from forming that can let air leak out.
Also, the leak might have been from a tiny leak from the valve stem valve. Upon filling the tire the valve fails to seat just right and lets air bleed out. These are pretty slow leaks and seldom show up even with the tire under water. (If one holds the tire under water a long time one can sometimes see a bubble at the valve stem tip form but it can take minutes of waiting and one expects to see a more obvious leak stream of bubbles.)
This can be a minor annoyance but it can also cause some trouble. I lost a tire on my VW from a leaking valve stem valve. At a fuel stop I checked the tires and found the one with a slow valve stem leak a bit low and topped it up and then took off down the highway. After some couple of hours of driving I got tired and sleepy and pulled into a rest stop. After a nap I got out to walk around a bit and noticed the tire with the slow leak was way low and had been for a while because the tread was obviously showing signs of the tire being driven under inflated. Thank goodness for a full sized spare tire!
What had happened was in filling the tire, topping it up, the valve stem valve didn't seat right -- it already had a questionable ability to hold air -- and this turned a small leak into a bigger one. In hindsight I should have spit tested the valves for any signs of leaking but I didn't think of it until I was changing the flat tire. Too late.
Sincerely,
MarcW.
Also, the leak might have been from a tiny leak from the valve stem valve. Upon filling the tire the valve fails to seat just right and lets air bleed out. These are pretty slow leaks and seldom show up even with the tire under water. (If one holds the tire under water a long time one can sometimes see a bubble at the valve stem tip form but it can take minutes of waiting and one expects to see a more obvious leak stream of bubbles.)
This can be a minor annoyance but it can also cause some trouble. I lost a tire on my VW from a leaking valve stem valve. At a fuel stop I checked the tires and found the one with a slow valve stem leak a bit low and topped it up and then took off down the highway. After some couple of hours of driving I got tired and sleepy and pulled into a rest stop. After a nap I got out to walk around a bit and noticed the tire with the slow leak was way low and had been for a while because the tread was obviously showing signs of the tire being driven under inflated. Thank goodness for a full sized spare tire!
What had happened was in filling the tire, topping it up, the valve stem valve didn't seat right -- it already had a questionable ability to hold air -- and this turned a small leak into a bigger one. In hindsight I should have spit tested the valves for any signs of leaking but I didn't think of it until I was changing the flat tire. Too late.
Sincerely,
MarcW.
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