Front tire pressure with loader/??

hunt4570 · Mar 31, 2020

So I just got a new pair of front tires for my tractor. They are 10-16.5 R4 industrial/loader tires going on a Kubota L3540 with a FEL.

My manual says inflate to 20 pounds, my old tires had a max inflation pressure of 45 pounds, these new tires have a max pressure of 75. The tire guy says not to go too low or they could unseat.

What do you guys run for air pressure in your fronts of comparable size??

4570Man · Mar 31, 2020

20 psi is almost definitely not enough. I’d inflate them until they’re satisfactory round with max load on the loader. I don’t think I’ve ever checked my M59 tire pressure but they’re a heavier tire. I ran my L3240 and L3800 at around 40 psi.

Peter 315 · Mar 31, 2020

40 psi is good.......

Patches · Mar 31, 2020

I run 50PSI in the front;40 in the rear with the hoe on

oosik · Mar 31, 2020

I REALLY think you should base your front TP upon the max load you will handle. I have R1's on my M6040. I run 40 psi. That is the max recommended on the side of the tires. I don't think that 45 or 50 psi would be wrong. Pick your heavies load - make a sharp turn - get off and look at the tires. If they are still well seated on the rims - then your are OK. If they are rolling off the beads - I'd up the pressure.

Remember the tires have a max rating of 75 psi.

hunt4570 · Mar 31, 2020

4570Man said:
20 psi is almost definitely not enough. I’d inflate them until they’re satisfactory round with max load on the loader. I don’t think I’ve ever checked my M59 tire pressure but they’re a heavier tire. I ran my L3240 and L3800 at around 40 psi.

Yeah, I've been running it at about 30. I got these new ones at 50 for now.

Texasmark · Mar 31, 2020

Believe the tire guy....he's your friend. I run my 35 rated 4 ply on the 2400 at 25. I run my 48 rated, 10 ply 12.5x18 on the 6530, at 18. If I am moving hay bales, or full 6' buckets of gravel with the FEL, I'll kick them up to 25. Too rough a ride if they get too high. The 2400 can have a full bucket of gravel and no noticeable sidewall flexing since it's low profile (50 profile ?)...perfect for FEL work. The 6530 has taller sidewalls (78 profile ?) and shows some slight bulging loaded, but being 10 ply I don't worry about it even though they are bias ply.

The sidewall usually references the max pressure and the load carrying capacity at that pressure. You pump those suckers up to max pressure, like you have to run your radial, metric, truck tires, and you'd need the seat belt to keep you in the seat...just look at the rating x 2 and the weight of your machine.

RickB · Mar 31, 2020

hunt4570 said:
Yeah, I've been running it at about 30. I got these new ones at 50 for now.

That is about where I would be.

art · Apr 1, 2020

In order to work with the four wheel drive and not destroy the drive line the front pressures need to matched to the rear. I typically recommend picking up the largest load and check the squat of the fronts and attempt to remove it with air pressure but not go over the recommended pressure. Then you will probably have to adjust the rears to compensate for the possible change in height of the fronts to give you easy dis-engagement of the four wheel drive on hard surfaces. That will reduce your drive line tension or windup or down on the drive system.