Loaded tire pressure

   / Loaded tire pressure #1  

sevilla

Silver Member
Joined
Feb 25, 2006
Messages
115
Location
New England
Tractor
L3830
Hi, I have a Kubota L3830 with loaded real industrial tires. I need to inflate the rear tires but I have a few questions. The manual states that the tires should be inflated at 20PSI but does not specify if loaded or not. Which is the correct pressure in your experience? Also, for loaded tires any compressor will do? Since I do not have one any recommendation for a reliable one?
Thank you so much.
 
   / Loaded tire pressure #2  
Hi, I have a Kubota L3830 with loaded real industrial tires. I need to inflate the rear tires but I have a few questions. The manual states that the tires should be inflated at 20PSI but does not specify if loaded or not. Which is the correct pressure in your experience? Also, for loaded tires any compressor will do? Since I do not have one any recommendation for a reliable one?
Thank you so much.
I've personally found that about 10 PSI will absorb the shock on my loaded tires and still provide an acceptable ride and load capability...they also have a 20 PSI sidewall rating...might want to look into a tire gauge made for liquid filled tires (TSC).
 
   / Loaded tire pressure #3  
Pressure is the same whether loaded or unloaded.

It has been my experience that if you are going to put air in calcium filled tires you should rotate the tire valve to near the top. I put a small amount of air in the valve stem to prevent any calcium from coming back into the valve, then use an air guage to check pressure. If you do get some calcium "spittle" back through the valve and into your air guage, clean it good and oil it lightly to prevent rusting/corrosion.
 
   / Loaded tire pressure #4  
As said - air pressure is the same whether loaded or not. I too like to run about 10 psi in mine, better traction & ride both. Mine are loaded with methanol and I use a spring-loaded tractor tire gauge.
 
   / Loaded tire pressure
  • Thread Starter
#5  
Thanks for the informations.
 
   / Loaded tire pressure #6  
From Installing Liquid Ballast in Tires | Gempler's
"Tires are designed to operate at maximum efficiency when they are at their Rated Deflection. With the tractor on a hard surface, deflection is the distance from the axle center to the ground surface divided by the distance from the axle center to the top of the tire. In technical terms, deflection is the value of the loaded radius of the tire compared to the unloaded radius. Rated deflection is the amount of deflection when the tire is deformed to its optimum or design footprint. Rated deflection for radial tires is about 85%, for bias tires it is about 90%. The correct pressure to achieve rated deflection depends on the load the tire is carrying. A correctly inflated radial tire will have a significant sidewall bulge or "cheek'. It may look low or flat but it is not. If you inflate a radial tire by "eyeball" until the sidewall bulge looks like that of a bias ply tire, you lose most of the performance advantages of the radial tire.

The tire gauge you use and the way you use it can have a big effect on what you think the tire pressure is. Always start with a good gauge, one that costs money, is easy to read, and is graduated in 1 psi increments. If your gauge cost 99 cents or came free from a feed dealer, has marks every 5 psi from 0 to 100 psi, and looks like it will break if you drop it, you are probably not going to measure pressures accurately.

Ideally, tire pressures should be measured in the morning, cold, or when the the tractor has not been used for several hours. As a tractor is used and the tires warm up, tire pressures will increase from 1 to 3 psi.

If tires have fluid ballast in them, the pressures at the bottom of the tire can be as much as 1.5 psi higher than at the top, depending on the amount of ballast. Whether you measure at the top or the bottom doesn't matter as much as whether you are consistent in where you measure. It is less messy if you measure with the valve stem at the top but it may be slightly more accurate if you measure with the valve stem at the bottom."

For anybody contemplating filling their own tires for the first time, this site gives some good step by step instructions with pics Installing Liquid Ballast in Tires | Gempler's

There is quite a bit of good information in this site Installing Liquid Ballast in Tires | Gempler's and this site http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/eng9920
 
   / Loaded tire pressure #7  
yep.. psi is psi.. load then fill with air to correct psi as per the manual / dealer /manufacturer specs.. etc.

soundguy
 
   / Loaded tire pressure #8  
yep.. psi is psi.. load then fill with air to correct psi as per the manual / dealer /manufacturer specs.. etc.

soundguy
Come on guys! Think about it. It's true...PSI is PSI, however, liquid compresses at a much higher pressure than air...if you add liquid ballast to a tire, you have essentially added material to the tire (decreased the internal volume) and you will find that maintaining the sidewall rated PSI on a loaded tire is going to be a pain in the butt! Literally. Much rougher ride quality. But, it's your butt, not mine!!! LOL.
 
   / Loaded tire pressure #9  
The info about sidewall deflection is priceless, and not often discussed here. Inflate your tires so as to achieve the recommended amount of deflection. That will be dependent on tire construction and axle loading. You can't read that from a book or sidewall, as axle loading is a variable. Most R-4 tires on CUT's are grossly overinflated relative to the load they carry and the contact patch they SHOULD be making.
Using liquid ballast is a tradeoff of convenience and dollars against traction, compaction, and ride. Convenience and dollars win 85% of the time.
 
   / Loaded tire pressure #10  
Come on guys! Think about it. It's true...PSI is PSI, however, liquid compresses at a much higher pressure than air...if you add liquid ballast to a tire, you have essentially added material to the tire (decreased the internal volume) and you will find that maintaining the sidewall rated PSI on a loaded tire is going to be a pain in the butt! Literally. Much rougher ride quality. But, it's your butt, not mine!!! LOL.
i dont think that most liquids could be compressed, at least the ones we use in our tires, so if you put 20 psi in your liquid filled tire then you would have 20 psi in the tire.
 
 
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