Tire pressure

Ive caught plenty of low tires with a thumper. Ive been driving for almost a year and have had plenty of flats, and about a hundred nails in the tires from plants, but never a blow out. I check my tires pretty religiously.

 

The only time I really get to gauge them is when we pick up on a drop and hook, which 99% of the time is all we do. Running team, the tires are never in a cold state to properly use a gauge on them when you start the day. I've caught many a flat or low tire thumping though. I also like to do a good visual inspection to look for nails and such so I know what needs to be fixed and which to keep an eye on.

If I have to fill a tire when I pick up a trailer and can't find a leak, I'll stop down the road 100 miles or so to check if I've lost air in it. I'll also visually look for wear signs on those problem tires on top of checking the air. I've had two that were flat on pickup, held air just fine even a day later, but began to wear very irregularly. One was flat, held air fine, but every 3 hours or so that I stopped the tire looked like it had 5,000 miles more worth of wear on it. I got that one replaced. I'm not sure what happen but I'm guessing whoever ran it flat maybe damaged the casing somehow, I don't know.

The receiver we go to on our dedicated run had a truck with bulk nails, not packaged, roll over 2 miles from the exit for the receiver. That was a tire nightmare for a good 3-4 months.

Now my question is, how much air do you put into a warm tire that's gone low in the middle of a shift? Say you run at 100 psi, when you fill the tire to that point while warm you're most likely not at that psi cold. Does the influx of cooler air that you're filling it with somewhat negate the difference? I've always wondered about this.

 

Put a gage to the tire next to the one that's low, and go from there...

I check my tractor tire pressure daily during pretrip- I'm solo, so they're cold. I'm paying for those tires, so having a blowout because I didn't check them isn't in the cards. We have a tire inflation system on the trailers so checking them is a major pain- besides the system is doing the work. I thump them just to make sure I don't have one going flat back there. I also do a walk-around whenever I stop. It's allowed me to pull road debris out of my tires before its done enough damage to cause a flat.

 

At least you're thinking to ask and are aware of those temperature changes.

Ironpony's suggestion make sense too, if you look at what the tire next to it is reading it will give you the "heated" pressure...as the thing cools down however, it will drop. The new air will be colder and more dense and when heated will expand, so don't excessively fill it to the same pressure, leave some head room for heating and expansion. Maybe 10 - 20% depending on the amount of difference, ie if the tire is at 80 it's lower (it's heated remember) and the tire next to it is 110 (100 psi, but expanded) you may want to go to about 90-95 as an example until you have a chance to cold check them. Check them later to see if the pressure has come up to the other tire's level...and adjust accordingly.

Your team situation presents a problem, one that an inflation system could take care of, but the trailers you pick up should be considered "cold" if they haven't run over a mile, and/or have been stationary for 2 hours...that's the usual time for tires to cool down for checking pressure...so when the team stops for shower, eats, etc.. if you have a 2 hour window...that's the time to check it.

 

Any of you drivers drop your tire pressure when driving the in the hot deserts. I would drop mine from 100 psi to about 93 psi on hot days over 98 degrees. An old trucker showed me this, don't know if it really helps, but I never had any problems using this method, and Iv never had a flat in the desert. I would have liked to use my tire thumper on my last trainer at CRST, but other than that I don't use them very much.

 

That is ABSOLUTELY the WORST thing you can do!!!!

Tires are designed to handle higher pressures as temperatures increase. Tires that are deflated run hotter - causing them to delaminate and BLOWOUT. NEVER, NEVER, NEVER drop your pressure below your cold pressure to compensate for higher ambient temps!!!

 

Those are most useful in the winter months for keeping ice from building up in the valve stem.
Crappy rims, old valve stems, fresh old recaps and you now have a second job keeping up with them ..
Those caps are like a last line of defense if they work right.
I hate tires.

 

I know all about drivers not looking after there tires yesterday i pulled into the pilot in battlecreek MI and as i was walking by a PAM truck at the pumps to go inside i could hear air hissing on the trailer upon closer inspection it looked like he hit a curb an knocked the tire bead back on the rim letting the air out the inly thing that saved him was the tire inflation system putting steady air to the tire, anyway when i came back out from the truck stop he was gone how he missed that walking back to his truck i'll never know kinda scary really.

 

Not really. I've heard drivers and maintenance say that's what the inflation system is for and ignore the fact regardless the backup to get somewhere, it's a rolling violation.
:smt102
There's just no getting through to people like that.

 

Stick guages are the least accurate when it comes to measuring air. Friction from the slider and dirt that ends up in the chamber make them useless for accuracy. Any good guage will be of the dial type with a needle and scale. Guages are most accurate from 3\4 to full scale readings. Little did I know how instrunment shop would come in usefull later in life.