What can cause low Tire Pressure?

[Scarpozzi]

I've had a few tires/wheels in the past that bled off fast enough that I took them to a tire shop to have them remounted. Sometimes it helps to pull them off and reseat the bead on the wheel. A good tire tech will inspect the tire and wheel. They can sometimes even scuff one or both surfaces to make them mate better if the problem keeps up. It may even be worth tightening or replacing the valve on that tire. Just takes a tool to unscrew the old valve and insert a new. If it unscrews too easily, it may have just been loose and bleeding a little air.

 

[BonzaiDuck]

Somebody talked about "buying Nitrogen". I don't. It's free. The tire-reseller, who covers a warranty that includes free balancing, rotation and inflation, does it for free -- under the warranty. The tire-reseller's facility is two miles from my home. So? Why not?

 

[manly]

Somebody talked about "buying Nitrogen". I don't. It's free. The tire-reseller, who covers a warranty that includes free balancing, rotation and inflation, does it for free -- under the warranty. The tire-reseller's facility is two miles from my home. So? Why not?

It was already explained why not. #1 Nitrogen is basically snake oil. It doesn't help or hurt. #2 You admitted because your tire shop only gives you nitrogen twice annually, you don't bother inflating your tires for upwards of 5 months at a time.

 

[NutBucket]

FWIW you can stop by Costco anytime and they'll check/fill with nitrogen free of charge. I wouldn't pay extra nor would I go out of my way to get it. There is some benefit but you'll *never* see it on the street.

 

[BonzaiDuck]

It was already explained why not. #1 Nitrogen is basically snake oil. It doesn't help or hurt. #2 You admitted because your tire shop only gives you nitrogen twice annually, you don't bother inflating your tires for upwards of 5 months at a time.

Tell ya what! My tires are six years old, and benefits under the warranty are at the reseller's discretion. I'm not far from shaving Lincoln's head, or I'd like a little more tread than I have left at the moment. I'm planning to get a nice set of Michelin All-Terrain steel-belted radials soon. With that, I'll check my tires monthly. I'm overdue for putting in an Amazon order for a new electric tire pump, which -- hopefully -- will be more pleasant to use than the old one. I bought the old one in 1992 for something less than $35. So again -- "why not?"

 

[dr1337]

Valve stem is pretty easy to check (really any sources are) with soapy water, and there's corroded rims, hardened/aged tires not sealing well at the bead OR slowlly leaking out micro-cracks in the sidewall that you can't even see until you get a flat and the bulge of the tire reveals them, at which point of flexing the sidewall that much they get much worse so if they are older don't let them get any lower than possible...

... tho' with winter coming on, if they are older this is a good time to replace them.

for a really strong leak this is true, but soapy water falls really short if your leak is really small. I've got some bead leaks (could be valve stem but they look okay) on my winter tires and I have to air them up about twice every month and a half. A very slow leak its very safe to say. With pressure changes this leak can be exaggerated but its still very real and something I have to keep in mind. I know most people really don't keep track of how much air is in their tires, and really you shouldn't need to unless they are leaking. But tiny leaks along the bead and valve stem are usually fine for long periods of time, especially without weather related pressure changes.

ik this is kinda a tangent but often small leaks wont really be identifiable through soapy water. if OP is suffering for a very small leak they might not be able to realize this with that solution.

 

[mindless1]

^ I've never found that to be the case. Granted, if it's REALLY slow leaking, then it just falls within my normal adjustment of tire pressure for late spring and late fall, that with the ambient temperature difference, winter needs more air to maintain the same pressure and vice versa for summer, so either way I'd be checking air pressure and adding if needed, but i suspect we know the leak isn't that slight or else the topic wouldn't exist. It's always about context.

 

[RLGL]

A slow leak in one tire can be the tire pressure monitor.

 

[dave_the_nerd]

When tires are installed, the quality of the bead/seal can vary. I've had slow leaks fixed by uninstalling/reinstalling the tires.

Damage or corrosion on the rim can cause a slow leak also. I've had leaks caused by bent/dinged rims, that were resolved by repairing or smoothing out the edges of the wheel.

Cold weather will lower you apparent tire pressure. (With extreme enough temp fall/spring swings, I've gotten in my car to 28psi tires at 20F, gone to work, and gotten in my car to 35psi tires at 70F in the afternoon to go home.)

I don't think nitrogen should make much of a difference in terms of speed of leaks, but it might slow corrosion on the inside of the rim/bead. But IME the Costco installers do a better job than most places - the tires I've had installed there almost never develop leaks, even with junkyard rims. Meth-head Jim at Bob's Tire Shack, not so much.

Ultimately, pay attention to your TPS, have a pressure gauge handy to verify, and keep a little air pump in your trunk to top the tires off when needed.