CX2510 Cab R14 Goodyear - What tire pressures?

[WB2ORJ]

New CX2510HST Cab has about 10 hours. I bought it with R14T 6 ply tires (Goodyear) and the service manual says to fill rear tires to 40 PSI but checking today the rear only have about 19 PSI ! (Yes I checked with another pressure gauge as well).
The rear tires are labeled for 40PSI and the front for 34 PSI. I know that for loader work I should inflate the front tires to the full recommended rating. What about the rear, how much lower can I safely go? The tire shape seems OK with 19PSI, no side wall sagging and the tires appears to be making full surface contact. I dont want to round up the tread but think 20 PSI is way too low.


Thanks in advance for any advice

 

[jeff9366]

The manufacture's suggested inflation rates are impressed into each tire.

First, I would check service manual's recommendation against manufacture's recommendation on the tire. I would favor the pressure recommended on your tire, at or near the high end due to your CAB.

Your shop manual may or may not predate the introduction of R14 tires three or so years ago.


When inflation pressures are too low, the tire bead can break, allowing the wheel to turn within the tire.

 

[5030]

Exactly, look at the sidewall.

 

[WB2ORJ]

I guess I'm reading too many Ag publications. They say that soil compaction can be greatly reduced by lowering the tire pressure and matching tire pressure with anticipated loads but they must be talking about big boy heavy metal tractors .

 

[jeff9366]

Your Kioti CX2510, even with a cab, is not going to compact soil more than a Cultipacker would when intentionally used to press new sown seed into the soil. Most compact tractors are made to be light.

Only at the heavy end of the compact tractor category, say 5,000 pounds bare weight, are tractors intentionally made to be heavy in order to pull wide, heavy implements in commercial agriculture. Fat, bulbous, low pressure radial tractor tires are an option for 5,000+ pound bare weight tractors.

MX = 4,000 pounds. M = 5,000 pounds.
Focus on the tractor wheels/tires.​

 

[ROUSTABOUT]

Make sure it doesn't say 40 psi when seating beads. My brother exploded one airing it up that much. I was there. Sounded like a bomb went off. Blew tire up like a balloon, was not fixable. He left the shop, wasn't in sun three minutes, boom !!!

 

[ksbrdmkr]

I've always ran the rear tire pressure of 12 to 15 psi on all of my tractors. Too much and you run risk of a stick pucture.

 

[bitbanger]

New CX2510HST Cab has about 10 hours. I bought it with R14T 6 ply tires (Goodyear) and the service manual says to fill rear tires to 40 PSI but checking today the rear only have about 19 PSI ! (Yes I checked with another pressure gauge as well).
The rear tires are labeled for 40PSI and the front for 34 PSI. I know that for loader work I should inflate the front tires to the full recommended rating. What about the rear, how much lower can I safely go? The tire shape seems OK with 19PSI, no side wall sagging and the tires appears to be making full surface contact. I dont want to round up the tread but think 20 PSI is way too low.


Thanks in advance for any advice

It is called out in the owner's manual, but all I have immediate access to is the service manual (below) and only for the open-station model. Technically these are for Ag/Turf/Ind tires - they don't explicitly call out R14s. Also if it's not noted in the tire section of the owner's manual, look in the ballast section of the manual: they will often advise a few psi higher or lower if liquid tire ballast is used.

In my opinion sidewall is only good for telling you max PSI for any application. Not necessarily the optimal PSI for that application (same logic for passenger vehicles... you follow the door placard, not the sidewall).

 

[WB2ORJ]

Spoke to my dealer (also was Kubota dealer for 20y before switching to Kioti). They never recommend inflating to maximum specs. My R14 rear tires (12-16.5, 6ply) is rated as 40psi but they routinely fill only to ~ 20psi. Front rated at 35 psi they advise from 20 -30psi depending on front load. If rear load increases to near tractor limits they would increase rear tire psi. They equate tire pressure to shock absorbers to use the low end of the recommendations except for high loads.