How do you thump your tires?

Thanks for the info and guess I'll stick to my program .

 

I've gone to service after doing a pre-trip over a couple tires and they were short 20-30psi. You won't hear a difference between 105 and 100, but you will notice a difference if it is low. I put my gloved hand on each tire as well, and thump the whole set to compare that they are even.

 

Would that be for heavy loads too?

Typically, Radial Tires are supposed to be 'flat" or they will wear out on the center. Under Inflated radials will wear out on the edges....

Industry related

As of April 1, 2015, a new regulatory update was posted that says an inspector must have a load/inflation chart for the given tire size and load range, and the jury is still out on how has this impacted the CSA violations.

According to Al Cohn, director of new product development and engineering support at Pressure Systems International Inc. (PSI), it is too early to tell what the impact on our industry will be. “This regulatory update specifically addresses giving citations for tires that are ‘underinflated.’ Up to now there has been no clear definition of an underinflated tire,” he says. “Since proper tire inflation pressure is based on the actual load, the only correct way to determine if a tire is underinflated is to measure the tire pressure and determine what is the load/tire. Then the inspector would review the load/inflation table to determine if a tire is really underinflated.”

Fleet Equipment wondered if this will validate fleets who may have been called into question before an under inflation standard was set. Cohn says, “The simple answer is yes. The biggest issue was for those fleets that ran light loads. Inspectors that based their “underinflation” standards on what pressure was molded into the tire sidewall should now receive a lot less tire underinflation violations.

“Fleets now understand that if their chassis, trailer or dolly is equipped with automatic tire inflation the CVSA inspector knows that the tires are being properly maintained so do not even waste their time checking the actual tire pressure,” says Frank Sonzala, executive vice president of PSI. “They move on to a trailer, which is not equipped with tire inflation systems. Fleets have told us that just by having automatic tire inflation cuts the inspection time by 17 to 23 minutes resulting in the tractor and trailer being productive and back on the road much faster. In a large fleet that is many hundreds of up time hours added fleet-wide every quarter.”

 

Holy crap a scientist and historian

 

Thanks for sharing !

I'm a conservationist, I want to leave this world the same or better than I found it and sharing with others along the way is my contribution to the lonely highway of trucking....

 

The article cited above by Dusty Road regarding the definition of "underinflated" is spot on. 25% of my miles are bobtail, where the proper inflation for the drives is about 70 psi. Another 50% of my miles are empty trailers, proper psi about 80 on the drives. ( Don't have the chart for exact numbers in front of me).
Point being the max pressure molded into the is for the maximum load ( single/dual). Less load less pressure. But short of a military style central inflation system controlled from the cab, who is going to start changing stuff?
You can bet a Frito Lay tractor trailer with a load of potato chips requires different pressures than the trailer that brought in 45k of potatoes

 

Heavy ball peen hammer hit it with ball side very noticeable difference in sound .. If two tires sound different gauge it .. I've caused flat tires by gauging in our Canadian winter due to ice jamming valve and causing a slow leak .. I thump every stop by habit

 

When I ran super singles( not by choice) I ran at night. The supers sat deeper into the trailer fenders than duals so they were harder to see, especially the rear tire. I was running in the morning and saw my rear single bulging. I gauged it and it read 40 psi. Not good. Found out that a plug went bad. repaired it. But 5 weeks later, while running at night, the tire went down ( The new plug failed and the tire deflated )and DESTROYED the back of my trailer. Unfortunately I was loaded and now I had 26 tons riding on a damaged front single, at an angle, on the side of the road. Since then I have ran duals all around and never regretted it.
I once checked my tire pressure with a gauge and had the valve stem stick, not fun. Now I don't check with a gauge unless near an air compressor.
Bought one of those air lines to blow up my tires, but it didn't have enough strength to inflate the tire with a load on, as I figured, but the only way I found out was with the load on. It was low due to a bad valve stem. Unfortunately the stem faced inboard on the outside tire so it took dismounting the tire to fix. Better a $50 fix then a blown tire and a $700 road service call and new tire.
I kick the tires every day because the fenders on the trailer are too low to swing a hammer. If they have a perceptible wiggle then the tire is low. I gauge them every Sunday before I leave for the week, but it's hard when in the shadows of the yard lights at night.
I check the tires at every fueling, what else are you doing for 5 minutes?? Found a chunk of aluminum in my trailer tire once, while looking them over at a fuel island. Luckily I have all new tires so I got away with it.
My tire inspection is a on-going inspection, not a once a day thing. I give them a look-over at every unloading and fueling. Things, like the aluminum chunk, can happen at any time. I feel the tires for excessive heat as well. Supers are horrible for heat. It really is scary how hot they can get with a load on after riding for 4 hours.

 

When I first got my infrared thermometer I used it alot. Recorded the tempos every time in a spread sheet. I've found that the singles in some of our trailers run significantly cooler than duals. I know that defies logic but the numbers don't lie, hand feeling does.

I'm also pretty sure that if they did run hotter, that the engineers and manufactures that spent millions of dollars developing them took that into consideration.

 

I'm going to kind of disagree here. I thump my tires every morning, check for bounce and "tone" as part of my inspection, if something sounds off, I'll grab my gauge and check them, I'm 50/50 for being right that one is low. Now, that is with a radial, go thump a bias ply, and you can normally tell when there's a 10 lb difference between tires.