Loaded-tires-air pressure?

   / Loaded-tires-air pressure? #1  

Gamemaster

Silver Member
Joined
Jan 19, 2005
Messages
106
Location
Erie,Pa.
Tractor
Kubota L2350DT
Hello to all, 1st time tractor owner ( Kubota L2350DT ),1st time writing to this site. I learned alot using this site and have not used my tractor yet, can't wait until spring !. My problem: Do loaded tires need to have air-pressure regulated ( 13.6-16 turf-tires spec. @ 14psi. ). The tractor was purchased late-fall and before storing in my garage in the city for the winter I read the manual and followed storage procedures. I checked the tires and water ran out of the rear's. I rotated the valve-stem to the top and water still runs out but not under pressure. I'm afraid to put my quality tire-gauge on the stem for fear of having water enter the gauge. Do the tires still have to regulated to 14psi even when loaded? Are these tires over-loaded?. Also, how can I tell if the tires have the correct calcium/water mixture? Appreciate the help and I'll mostly likely have more questions from this tractor-virgin in the future.
 
   / Loaded-tires-air pressure? #2  
Yes, the tires' air pressure still needs to be regulated as if they had no liquid in them. To get the proper maximum amount of liquid, you need to jack a tire up to take the load off of it with the valve stem at the top (12 o'clock position). No liquid should come out then. Then go to your local auto parts store, tractor dealer, etc. and buy an air/liquid tire gauge. They don't much, if any, more than a regular air gauge.
 
   / Loaded-tires-air pressure? #3  
Jack the tractor slightly off the floor to measure the pressure. Again, you'll want the valve stem at the 12 O'Clock position.
I use the draw bar bracket as a jacking point on my 790. the tires just have to be a fraction on an inch off the floor.

If you already did that, the tires may be overfilled.

As far as a pressure gage, go to your local Tractor Supply, NAPA or dealer and get an air-liquid pressure gage. They're spring loaded to force any liquid back out when you check the pressures. Of course, that means you can only check pressure when your hold the gage against the valve stem.
 
   / Loaded-tires-air pressure? #4  
Thanks Bird, it's amazing what I learn on this site /forums/images/graemlins/grin.gif
 
   / Loaded-tires-air pressure? #5  
If you're getting fluid out of the valve stem with it at 12:00, you have too much fluid in the tire(s). That isn't the end of the world though. (as long as it isn't too much above the stem) Fluid won't compress. Air will. The air cavity at the top gives the tire some cushion when you are bouncing over rough terrain. If there isn't enough air-space, you can split an innertube. (I've seen it done) If the fluid is just slightly above the stem, no harm will come most likely. Use a tire guage meant to work with fluid filled tires. They are primarily designed to work with corrosive CaCl filled tires. The "stem" will be spring loaded. That allows you to pull and release it to purge the fluid from the inside of the guage.

As far as measuring tire pressure with the tractor raised off the ground, that might be usefull if you run your tractor with the wheels in the air, but I want to know the TRUE WORKING PRESSURE with the weight of the tractor resting on the tire. On my biggest tractor, (Deere 4955. 18,275 lbs w/ ballast) that effects the rear tire pressure by more than 5 pounds. When you're talking 12 pound tire pressure to begin with, 5 pounds is a BUNCH. JMHO. John /forums/images/graemlins/grin.gif
 
   / Loaded-tires-air pressure? #6  
Too much fluid in the tires can be a problem if you are in an area of the country that has any sustained below freezing temperatures. I don't know of any fluid used in tires that doesn't have a significant water content. Water expands when it freezes. Just something to be aware of.
 
   / Loaded-tires-air pressure? #7  
Is there a consensus on how much liquid should be in a tire? Would you say that, for example, no liquid should come out if the valve stem is at 10 oclock?
 
   / Loaded-tires-air pressure? #8  
</font><font color="blue" class="small">( Is there a consensus on how much liquid should be in a tire? Would you say that, for example, no liquid should come out if the valve stem is at 10 oclock? )</font>

Well established quide line from tire & equipment manufactures- 70% by volume.

Andy
 
   / Loaded-tires-air pressure? #9  
Ballaststar.com has tables for fluid capacity. Check out this prior thread also web page
I found that when I filled my tires to the perscribed amount that water did come out of the valve at 12 o clock (wheels jacked up) but only when there was zero pressure in the tire. I think in my case the weight of the antifreeze in the tube/tire may have caused this, when I pressured up the tire it took a lot of air to get to the correct psi which indicates to me a large air cavity. Others are correct that if indeed there is too much ballast then there will not be an air cushion, my suggestion would be to let all the air out and then see how much volume of new air is required to get to pressure, not real scientific but it works. /forums/images/graemlins/laugh.gif
 
   / Loaded-tires-air pressure?
  • Thread Starter
#10  
Bear with me, 1st tractor...no experience at all..Your suggestion is to let all the air out and re-pressurize, but the only thing that came out was water when the rear-tires were on the ground or up in the air. If any owner walks up to his/her tractor and pushes in the valve-pin of a loaded tire what releases...just air or air/water spray?. The water ran out of my stem at a gravity level. It didn't have any noticable pressure at all, when tire was up or down.. I ordered a tire-gauge from a local tractor-tire dealer. It comes next week, neither Tractor Supply or Napa had one...figure that ? It sounds like a couple of possibilities here. I have no past history on the tractor...auction sale..owner died..but you make it sound like there could be no pressure in the tire.. I also read above that pressure should be checked with tires on the ground. Really gett'in confused now..need help..What would be the steps to take? My guess, jack-it-up,rotate stem to 12:00,push in valve-stem pin until water stops coming out, add some air, put it back on the ground and set pressure. Just taking a stab at it . Input would greatly be appreciated...Enjoy your weekend ...TO ALL
 
 
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