air pressure in 12.4 x16 ag tires ?

[Grumpy Old Man]

New to me John Deere 855 with 12.4 x 16 ag rears and I'm wondering what tire pressure to run rather than just filling till hard ,any advice I can use ?

 

[RaydaKub]

Check the sidewall for printing?

 

[Gary Fowler]

There should be a bit of a buldge in the sidewall at the ground contact point for proper traction and smoother ride. Overinflation will cause center tire tread to wear faster just like auto tires. 15 PSI should be adequate for your uses on rear tires. With FEL you need more in front to keep from rolling them off the rim when loaded and in sharp turn. As suggested, check sidewalls for max pressure and dont exceed that. Usually about half the max on rear is ok and up to the max on fronts works for max loading with FEL. Same holds true for front. Load the FEL with max load and then air up till you have just a little flex in sidewalls or max pressure obtained.

 

[Grumpy Old Man]

There should be a bit of a buldge in the sidewall at the ground contact point for proper traction and smoother ride. Overinflation will cause center tire tread to wear faster just like auto tires. 15 PSI should be adequate for your uses on rear tires. With FEL you need more in front to keep from rolling them off the rim when loaded and in sharp turn. As suggested, check sidewalls for max pressure and dont exceed that. Usually about half the max on rear is ok and up to the max on fronts works for max loading with FEL. Same holds true for front. Load the FEL with max load and then air up till you have just a little flex in sidewalls or max pressure obtained.

Thank you for the honest advice ,the fronts are foam filled and heavy so no worries there , I just thought asking someone who new the right answer was smarter than relying on the sidewall info ! ,Thanks again !

Grumpy

 

[MHarryE]

google your tire supplier, find their data (everyone I have looked at has their data on line) and check for load inflation tables. Inflation recommended in my Kubota OMM is equal to the max inflation pressure on the sidewall and also the Titan tire book. The load inflation on all brands that I have checked exactly matches the Tire & Rim Association standard which is no surprise as tires are standardized worldwide. Going by sidewall bulge could be a recipe for failure but you will find that out when you try to get warranty on a failed tire. A good tire technician can tell an overloaded tire failure. Our larger ag tires, all radials of course, have a large bulge at recommended inflation pressure although our tractors are not loaded and only our JD 6230 gets loaded heavy (it is our large loader tractor).

 

[techwrtr2]

I fill the rear R4's on my 855 (same size I think) to 15-20psi. Fronts which are not foam filled go to sidewall max as I also have a loader and am known to load it heavily.