Tire Pressure Gauge Failure

We had a tire pressure gauge fail that allowed an 'over-fill' of 20 psi on an 80 psi tire.

While pouring through Pre-Trip inspections I had one of my 'young guns' grab a tire pressure gauge off the shelf of 10 gauges and help me check the 17 tires carrying us to an airshow this weekend.

While checking a trailer first he decided to look at all the tires before deciding to pull out an air hose.

This trailer had been parked for a few months so when he said everything was down 30psi, I wasn't surprised.

He began to fill the first tire while I re-torqued wheel nuts and did an under chassis inspection. He filled for quite a while, stopping twice to check progress then continued filling. I watched when I stuck my head out from under the truck but he was quiet and appeared to be having success.

He must have had that gut instinct kick in along with the "If you're not sure, don't do it", chime in the back of his head because he stopped and said, "Something is wrong, it is not taking more then 50 psi."

We checked compressor, chuck and air-lines then I asked him to put the gauge on a different tire he knew had been inspected the day before.

Sure enough the gauge only went to 50 psi and stopped. We knew this tire had 80 psi in it yesterday, so we checked another, which also stopped at 50psi. The gauge bar moved freely in and out of the shaft and was rated to 130 psi.

After discarding the tire pressure gauge and grabbing a different one we found he had run the max. 80psi tire to 100psi.

It's been hot and humid here which may have been a contributing factor, along with a cheap gauge and a lack of 'maintaining' the diagnosing device.

I believe we got lucky and the 'splatter factor' was limited. We know the s#!t is going to hit the fan, we just don't know how far it will splatter.

I hope all of you get lucky this weekend as well.

Old video of dyno test tire failure. This one could have been bad with an observer standing next to the tire.

[media]http://www.youtube.com/watch?v=BNB-ZbNpfBA[/media]

Inflating tire failure safety video.

[media]http://www.youtube.com/watch?v=dKlJJqHFfoQ&feature=related[/media]

No matter why type of air pressure gauge reading instrument and the word instrument here is crititcal - should never be bounced around in a tool box/cab etc.

It can deviate the air pressure readings by knocking the calibrations off when its time to read a proper air pressure.

Here is a tool for the fleet garage I made so at the beginning of every week the mechanics have to sign off they have tested their gauges for proper readings.

A proper air pressure for any given road vehicle can surely increase your fuel mileage by a good 3%.

just my lousy .02 cents worth.

I use a clip-on chuck with a pressure regulator set to under the recommended pressure for the tire being inflated. I used three hoses to move the inflation from anything of value. I did two 16x8 split flange wheel mountings today off an M37, didn't have a cage so the tire-wheel assembly was wrapped with 3" web strapping.

Nothing is fool-proof, including the regulator so I monitored the pressure gauge and listened for flow. The regulator was placed between the first and second hoses so my observation point was far removed from the tire-wheel.

I have seen the damage and injury from a 5 ton 11x20 tire. Unfortunately, the US Army didn't believe in clip-on chucks so the soldier was seriously injured with both eardrums ruptured, collapsed lung and concussion. The inflation cage was damaged beyond repair but retained all major parts. The inner tube and boot were shredded, coating the soldier with black dust. The soldier's BDU jacket was completely torn off along with his undershirt.

Split flange tires seat beads early since there is no bead retention hump. The split flange inner hub CAN hang the bead, this is the most common cause of split flange inflation explosions. Tire cages CAN be the cause here, especially if the rim is cocked on the tire. Inflating the tire-wheel flat, ring up can prevent this IF AND ONLY IF the wheel assembly is wrapped to prevent the ring from flying.

I would be cautious abpout using straps, as the split rim might cut them, if she blows. I use a chain with two wraps @ 180 from each other, spaced half way from the rims ends on the split rim. I don't have the cage. Use the remote valve and clip on chuck w/short hose. Put about 5 # or less in there, and go tappy tappy on the rim, to make sure its seated. The stand it up, do the chain tricks, etc, and stand around the corner.