Dump Truck Tire Pressure

[mbavers]

F750 single axle, new bias ply drive tires, 1000/20, load range H (6000+ lbs each when dual). I drive 10 miles to the gravel pit empty, then 10 miles back fully loaded (maybe a bit over). I am half on paved roads, half on rough gravel roads. My max speed empty is 30-35; max speed loaded is 20-25. At max weight the manufacturer's recommended pressure is 105. My tire dealer wanted to use 80-90 psi. I had them all aired to 95-100 cold. Since I can't change the pressure between heavy and light, what pressure would you use?

 

[redneckracin]

I'm pretty sure that based and the manufacturer. The model of tire. Speed and weight they will give you a chart for their recommended tire pressures. I know Michelin does this.

 

[mitch504]

The good news is, it's actually not critical in your application, since your speeds are low and your distances are short.

The technically correct tire pressure at any moment depends on 2 factors, load and speed. What actually kills a tire is flexing, and the heat built up by it. If you actually dig into the charts, you will find that that tire will be capable of carrying a good bit more than it's 6000 lb (at 55mph) rating at 25 mph.

Ok. Real world answer- run it at pressure appropriate to highest load and speed it will see. If you are running at too high a pressure (empty truck), you will wear the center of the tread more than the edges and shorten the tire's life a few percentage points. If you run at too low a pressure, you will blow out the tire, or shorten it's life markedly.

What you are doing I am sure that 80 to 105 psi is fine, but personally I would run about 100. The most important thing is that the pressure be very nearly equal between 2 tires side-by-side, since more than 3-5 psi difference will severely overload the inflated tire.

 

[Truck Shop]

Agreed-Make sure that the valve stems and grommets were changed. Those leak with age.

 

[crane operator]

Agreed-Make sure that the valve stems and grommets were changed. Those leak with age.

Tube tires. Some of us are still in the stone ages.

 

[Truck Shop]

Tube tires. Some of us are still in the stone ages.

Talk earlier about tubeless, but we never have a tire mounted especially on aluminum rims without having the stem grommet seal changed or just install new stems. Those corrode
real bad with road de-icing fluid and start leaking. And few tire shops change those out steel or aluminum wheels.

 

[mitch504]

Uhh, TS, uhh, are you ok?

They don't make tubeless 10.00-20s

 

[mbavers]

The good news is, it's actually not critical in your application, since your speeds are low and your distances are short.

The technically correct tire pressure at any moment depends on 2 factors, load and speed. What actually kills a tire is flexing, and the heat built up by it. If you actually dig into the charts, you will find that that tire will be capable of carrying a good bit more than it's 6000 lb (at 55mph) rating at 25 mph.

Ok. Real world answer- run it at pressure appropriate to highest load and speed it will see. If you are running at too high a pressure (empty truck), you will wear the center of the tread more than the edges and shorten the tire's life a few percentage points. If you run at too low a pressure, you will blow out the tire, or shorten it's life markedly.

What you are doing I am sure that 80 to 105 psi is fine, but personally I would run about 100. The most important thing is that the pressure be very nearly equal between 2 tires side-by-side, since more than 3-5 psi difference will severely overload the inflated tire.[/QUOTE

I'll stick with 95-100 psi.
"......tire will be capable of carrying a good bit more than it's 6000 lb (at 55mph) rating.............." Yeah, I found that out by bringing back a full load on one tire (on one side) on two different occasions. I figure the good tire was carrying about 12,000 lbs.

 

[mbavers]

The good news is, it's actually not critical in your application, since your speeds are low and your distances are short.

The technically correct tire pressure at any moment depends on 2 factors, load and speed. What actually kills a tire is flexing, and the heat built up by it. If you actually dig into the charts, you will find that that tire will be capable of carrying a good bit more than it's 6000 lb (at 55mph) rating at 25 mph.

Ok. Real world answer- run it at pressure appropriate to highest load and speed it will see. If you are running at too high a pressure (empty truck), you will wear the center of the tread more than the edges and shorten the tire's life a few percentage points. If you run at too low a pressure, you will blow out the tire, or shorten it's life markedly.

What you are doing I am sure that 80 to 105 psi is fine, but personally I would run about 100. The most important thing is that the pressure be very nearly equal between 2 tires side-by-side, since more than 3-5 psi difference will severely overload the inflated tire.

My reply was somehow erased. I will run 95-100 psi.
I limped home on two different occasions with a heavy load and one tire on one side flat, so the good tire was carrying about 12,000 lbs.

 

[Truck Shop]

Uhh, TS, uhh, are you ok?

They don't make tubeless 10.00-20s

I realize that-I was just throwing that in on top of the tire discussion. I would be willing to bet no one on here has the stems changed on anything they have that are tubeless unless
it has a leak.

 

[mitch504]

Yeah, I was just twisting your tail.

I sure didn't change stems every time when I was in the trucking business. I had a bunch of units that only hauled scrap metal and demolition debris. They averaged 2 or more flats a week each!

I had others that hauled dumps (lime, fertilizer, sand and gravel) in North and South Carolina, they got about 2 a month.

Then I had 2 that hauled containerized paper in Ga, SC, NC, and Va. My tractors would get a year out of a set of tires, and the container chassis tires were an unmitigated disaster that the shipping lines blamed us for!

One of the best days of my life was the day I sold all my trucks but one. Then, (idiot) I bought some more, but I only have 1 full time driver-operator, and 1 part-time, and me; so it's not toooo bad.

I used to hate The Maintenance Council. They made blanket pronouncements that applied to longhaul work, and then the state took them as gospel. We can argue about all those after supper if you want.

 

[mitch504]

My reply was somehow erased. I will run 95-100 psi.
I limped home on two different occasions with a heavy load and one tire on one side flat, so the good tire was carrying about 12,000 lbs.

Yep, they will do it if you hold your mouth right!

Probably the greatest advantage to tubeless tires for short haul work is that the tube valve stem will usually slip inside and ruin the tire from the inside if you run it flat. You used to be able to buy clamps that went on the stems to keep them on the outside, but I doubt they make them anymore.

 

[Truck Shop]

We can argue about all those after supper if you want

It's supper where you live out here it's dinner. Flats? Tear down a flat house and you will see flats-you can't buy enough monkey grip. How many on here know what a flat house is?

 

[mitch504]

Worst flats I ever saw was when I was mechanic/foreman for a trucking co that had a contract to haul iron ore from the dock to the other side of the steel mill. We used 5 tractor-trailers, plus a spare or 2. I worked night shift when we had a ship in. I usually had a tire man, and still changed a bunch. We used to bring a 16' flat bed loaded with mounted tires in every evening, and haul the flats back to the shop in the morning. On a bad night, I'd have to go get more before shift change. We ran all tubeless and very seldom destroyed a tire, just patched and sent back.

We had a tire man in the shop who could patch 40 in a day, by himself.

And nope, never heard of a flat house.

 

[Truck Shop]

Grain elevator