Is It OK To Deflate A Hot Drive Tire On My Truck?

Semi truck tire? I almost guarantee you've never seen a truck tire blow from too much pressure.

You may have seen a compromised casing, or casing that was run low blow, but those failures weren't caused by too much PSI.

Do you have a relative that's a member here?

 

No you haven’t. Unless you can guarantee that those tires had never been run under inflated, had never hit a curb, etc.

 

I don’t know why but something keeps bringing me back to this thread. I guess I’ll subscribe.

 

Flashbacks of that one guy……his name escapes me right now. Backing into docks and what not. Hub oilers dude.

 

Expedite it.

 

The reason for that was they had sidewall damage due to bring under inflated in the past. The sidewall cords were fatigued. The extra psi was all they needed to cause the injury to fail.

In many cases sidewall damage is not visible from the outside. The tire has to be dismounted and inspected on the inside. You have to look for signs of a heat/ flex ring. Darkening, powdering, or a distinct visual pattern called marbling of the liner. That is why a tire should always be removed from wheel and inspected before patching it. AND a tire the has been run underinflated more than 50% of its max psi should not be inflated until after an off the wheel inspection. Specially if it is already hot from use. That is a grenade waiting to happen.

 

I came to trucking from aviation. In that industry if you ARE NOT over-thinking your options you aren't keeping up.Think of a contest where only the most overly prepared player is doing enough. And over-thinking is part of my personality. So I don't mean to slam you for thinking ahead. I am looking at the time and energy of doing the task to have your tires at optimum pressure 24/7 compared to the benefit plus living under HOS. The easy part is getting down to the perfect lower tire PSI. But what about inflating trailer tires extra 30-40 PSI? And the larger the company you drive for the more likely they will be using a central air inflation system AIS to keep the trailer tires inflated and all of those tires will have hoses connected to the air stem at all times. While you may think, great I just change a setting on some menu somewhere and then the truck will inflate/deflate to the setting I choose, I don't think that is how they work, at least not on the trailers my big company used. So that means you spending all that time to crawl around disconnecting the AIS hose from each valve stem and draining air and then hooking the AIS back to the stem, 8 times for each pressure change. Also, like pointed out earlier, you handling all of that for all of your trailer tires puts you, not the company, on the hook if a tire fails and causes damage to anyone else.

When was the last time you increased a trailer tire pressure by 30-40 PSI? It is not like bumping up 1 tire on your car by 5 PSI. It takes time and constant force by you to keep the air chuck connected, while you kneel on the ultra-sanitary surface of the truck stop. Even though they make air chuch where you don't have to manually hold the air hose to the valve the valve stems, especially inside tires, may not have enough space around the stem for such air chuck. Not to mention if you air up tires using your truck's air compressor and a long glad-hand hose it is pretty slow. 8 tires will take a lot longer than you probably imagine. So what about using a personally provided air compressor which take up space in the truck? Maybe you can get away with the modern small devices, I think that means longer time to increase PSI per tire. That will mean avoiding the manual holding pressure on the chuck for each tire, you still have reconnecting the AIS to each stem. And this means maybe doing this whole task in good weather and bad, day and night, hot and cold, and low and high altitude, and maybe twice per day.

I see this consuming 30-60 minutes per inflation event, and that's hoping you never brake something in the process or you never run across a stubborn component that is rusted in place or brittle and fails during the exercise. I'm exaggerating slightly when I suggest maybe it would be better for you to quit your job and work on finding or building a user-defined air-inflation system with dashboard controls and then making a million dollars per year selling that to the industry than doing this manually, under HOS as a driver. Part of my over-thinking is thinking about the downsides of ideas, the worst-case scenarios, and assuming I'm an idiot because there is an easier and safer way to accomplish what I want but I am too stubborn to stop building my overly-complicated solution half-way through the first use to drop my plan and adopt someone else's idea.

It's always been ingrained in me that tires fail more often from too low pressure than from high pressure. So I can see your "lower PSI while empty" causing you to have more blowouts, not fewer blowouts. And since nobody is perfect imagine explaining in court how the one time you forgot to boost PSI from the empty trailer setting to the loaded trailer setting and it caused an accident with major or fatal consequences, it was because you were a 4-D Chess type of driver and not a reckless driver. I would like for that system to be standard now. You may have the drive to make such a system. I'm not saying stop all efforts on such and idea. I'm saying, I think it's too much effort, time, and risk for me to add into a typical day of truck driving. But I hope you do find the solution which would make that idea easy and widespread.

 

I've ALWAYS been told most tires fail from under-inflation. Low pressure means more sidewall flex, which heats the tire. And while everyone is 300% certain from seeing tire debris in the road that the failed tire was a re-cap, most tires that fail from low pressure fail and leave the tread section (gator) whether the tire is virgin rubber or re-cap.

 

The newer PSI systems do bleed air out at whatever you have set + X lbs. Why you see the light come on for s few minutes after it's sat for a while and cooled down. If you bleed the air out and hook the lines back up it will just go back to where it's set.