9.5-16 R-1 rear tractor tires, Calcium filled. I want them at 20 PSI.

[JasperFrank]

I'm not sure if I can trust my tire gauges.. One is electronic and the others are the Slide Type. Getting very different readings. The valves spit water, even at 12 oclock. Electronic says 18.5, the sliders just give me 7 or 8 PSI. I can set the air compressor at 20 but it will not fill at that low a setting. I can only hear bubbling if the Compressor is set to 40. Don't like guessing since there are warnings not to go over 38 psi. How do you guys set the psi on Calcium filled tires?

 

[RjCorazza]

Maybe letting the valve stem spit out for a while will clear the fluid (assuming the tires are not over full with the calcium chloride). If I had to trust one gauge over the other, I would likely side with the manual slider.

 

[3Ts]

+1
Also, with your air gauges be sure they are rated for filled tires. Especially the slider type, there is a spring in there that will corrode and give incorrect readings. A new slider gauge will work for awhile, but not long. I got mine at Gemplers.

 

[LouNY]

Once a tractor tire is aired up the first time I seldom use a gauge on them.
But I almost never take them any wheres near max psi.
I just look at them under load and make sure the sidewall bulge is not excessive and that I'm getting a full foot print on the ground.
To check your gauges you can get a valve stem with threads to screw into an air line fitting and compare them of course then you need several to try and decide which are the correct readings.

 

[RPW]

Just a swag, sounds like your tires might be filled to the top. I was told not to fill more than 75 percent. Also wondering what the reason for 20 PSI.

 

[JasperFrank]

Reason for 20 PSI is I'm going to be moving large, 300 lbs, rocks with a FEL, in an area with slopes and uneven ground. The tractor seems more stable and predictable against roll over with the tires inflated, and weights added. The fronts are at 28 PSI, which is the max load PSI, the Firestone Chart for the rear tires says I can do 1100 lbs at 20 PSI. And all the way up to 1360 at 28 psi Only 825 at 12 psi. The tires are old so I don't want to push them to the limits. I'll also have a box scraper on.
I may be technically wrong as to if higher PSI leads to more stability, but seat time tells me the tractor is less likely to go on three wheels with higher PSI. All wheels have already been set up for wide stance.

 

[LouNY]

The more load in your fel the less the rear tires will be loaded.

 

[Redlands Okie]

Higher PSI does allow for more load and stability for FEL work.

 

[fatboycowen]

I destroyed a good working air gauge very quickly using it on Calcium filled tires. As i recall, it worked once on the tractor, and two weeks later, the reading was substantially off. The calcium did bad things inside. Couldn't tell by looking at it. It functioned properly, just was way off.

If you previously used the digital gauge on those, it's probably bad. The same could be said for the other. Get another gauge.

 

[LouNY]

Higher PSI does allow for more load and stability for FEL work.

Not in the rear tires, in the fronts yes.