Tires RK37 tire pressures

[DonRybak]

Anybody know the tire pressures on the RK37 with industrial tires. Only reference I can find is a chart in the manual that appears to show the sizes but I don't see anything about pressures. Thanks........Don

 

[Gregster613]

You are in the same place I've been in; everyone is going to tell you to look in the manual for the proper pressure but the manual doesn't say! I've followed these types of questions for years with no finding an answer. I put water into my tires and wanted to try find out what pressure was proper to refill them with air after. No responses. So I just used how the tread tracks on asphalt with a wet tire. As long as I'm getting an even track the pressure must be right or at least close enough to not bother me. I wanted the full width of tire to track and that's what I've used for years. I don't even remember the amount of air I used; maybe 12 - 15lbs? Sorry I can't be of any other useful advise - just what I use. Greg

 

[DonRybak]

Thanks for the response Gregster, I love my tractor but the manual is pretty lame in some respects. How hard can it be to add a chart in the manual or place a decal on the tractor somewhere listing that info? I wonder what the folks on the assembly line refer to? Since there has been no response from the RK rep I'm wondering if the assemblers don't Have anything written to go by either and just add air until it looks good. Have good weekend.......Don

 

[DonRybak]

While at my local Rural King yesterday I questioned the person i bought my tractor from as to what the pressures are. Right off the bat he knew the rear tires were to be at 20 psi but said he'd have to research the manual for the rear. I told him I had no luck finding anything in the manual pertaining to the tire pressures. He took my number and said if he couldn't find it he'd call someone and find out. A couple hours later he called and said that the fronts were set at the max inflation pressure of 45 psi as written on the tires themselves. This morning when I went out to feed my horses I noticed on one of the rear tires the number 20 faintly written in chalk. Guess it's been there all along and I never paid any attention to it. He did say that when checking the rear tires to make that the valve stem was at the 12:00 position to keep the beet juice from being forced into the gauge........Don

 

[g8erh8er]

While at my local Rural King yesterday I questioned the person i bought my tractor from as to what the pressures are. Right off the bat he knew the rear tires were to be at 20 psi but said he'd have to research the manual for the rear. I told him I had no luck finding anything in the manual pertaining to the tire pressures. He took my number and said if he couldn't find it he'd call someone and find out. A couple hours later he called and said that the fronts were set at the max inflation pressure of 45 psi as written on the tires themselves. This morning when I went out to feed my horses I noticed on one of the rear tires the number 20 faintly written in chalk. Guess it's been there all along and I never paid any attention to it. He did say that when checking the rear tires to make that the valve stem was at the 12:00 position to keep the beet juice from being forced into the gauge........Don

My RK55 industrial tires are pretty much rock hard, even the sidewalls. I just assumed they fill the things to max pressure and call it good. I may let a little out to see if it softens the ride a tad.

 

[boomer1025]

All the tires I have ever seen were marked on the side wall with the Max pressure and Max load rating for the tire. I fill mine to just about Max pressure as marked on the tire.

 

[Tennsawdust]

You should be able to go down to 15 PSI without any problems if you aren't running it on the road much.

 

[Ishkatan]

The tire sidewall has the pressure along with tire size and load ratings. Just have to look. I noticed it on a tractor in the lot but don't recall which type of tire it was - but I got a picture.
Since it is full of Rimguard up to the valve I would run it at a bit less than 20. And check with the valve at the top of the wheel...

 

[SARG]

I've seen this on forums frequently ........... The MAX pressure on the sidewall of ALL tires is the absolute maximum the manufacturer puts on to cover their butt ........... and is definitely NOT the pressure the tires should be operated with.
If you need another clue....... check your vehicle tires and then look at the sticker on the door jam that provides the operating psi for the vehicle.

 

[the old grind]

The cert label on your car or truck takes into account specifics to its particular configuration (body type, engine option, weight distribution, etc) for safe handling, and most importantly safe braking. Max tire pressure ratings are for max loads. The goal is always to maintain a proper contact patch with tire size and expected use. Butt-covering or design criteria/specs?

What changes radically with filled tires is the progressivity of the springiness/cushion of the air chamber within. (Boyle's Law) btw, I'm in favor of using contact patch to adjust pressure regardless of the amount of fill. At say 75% fill a tire will squat far less under the same load than with just air because its net pressure rise will increase far more rapidly.

I suggest a 20 lb min to keep filled tires on rims, but also to let the ride be your guide and that traction has less to do with tire pressure that many of us believe.

 

[Midniteoyl]

If you know your tires manufacturer and size (hint: they are written on the tire itself.. ) you can look up the Tire Inflation Table and learn the the weight ratings at different PSI ranges. Sometimes you can't find a PSI range, but can find what PSI the tires rating was given for and extrapolate from there. My Titan R14T was rated @ 4080lbs @ 30psi, which was below the 41psi Kioti says in the manual, and even lower than the 44psi on the sidewall, for example.

 

[hornett22]

I have a smaller tractor, a Mahindra 1626 with washer fluid in rear tires. I run 10-12 psi in the rear and 30 in the front. Never had an issue. Rides better and traction is much better.

If I had an RK37, I'd probably run about the same psi

 

[LouNY]

I am always amazed at the number of people that think the maximum inflation pressure on the tire is the pressure they should run.
Especially when they usually are not even loading the tire to half of it's load capacity.
I normally run my rear tractor tires around 12-15 psi, I have gone as low as 8 psi and as high as 25 PSI,
the 25 was when I was moving a lot of material with my rear mounted forks and maxing out my lifting capacity plus on the
3 point. Upwards to a bit over 2 ton on the forks.
My front tractor tires it depends if my tractor is carrying a loader or not and what I'm going to be doing it can vary from 15 psi to 5 psi over the listed maximum pressure.
Also on a 4wd tractor the tire inflation pressure will vary the static loaded radius or the rolling circumference which can throw you tires desired lead/lag all out of spec. A heavy loaded loader squashing the front tires down in 4wd the rears will be pushing the front, while a front tire at maximum pressure with the loader remove is likely going to be spinning the tire trying to pull the rear faster.

 

[Blue Mule]

I have the same 43" rear R4 tires on my tractor that RK uses. The R4s are 6-ply and are rock hard, so I strongly recommend LESS than 15 PSI to ensure decent traction. At 20 PSI they become concrete blocks and slide a lot. I think currently mine are at 12 PSI rear, with fluid in them.

 

[Rob41]

I guess I need to get out and roll my rears around so I can see what the pressure is. I'm just going to guess the previous owner had them set however the dealer had them, probably around 30psi. I'll have to try out 20psi and see how that feels.