I have had both valve stems fall out of the front tires on my GC1710 TLB. The tires are very ridged, and actually ran one of them for who knows how long with no air, even with weighted bucket. I only noticed because the tire was separating from the bead as I drove. I eventually found a tire dealer with a machine that could replace the stem and re-mount the tire. Now I gotta do the same with the other one. But they don't do ballast. Anyone use wheel weights on the front (or back)? I have noticed since this problem, the front seems very tippy with the backhoe on. I keep my tractor in my garage and even though we have been having REALLY NICE WARM weather (60 degrees today in upstate NY!!!) I see seepage from the rear tires. Any thoughts on replacing the liquid ballast with rim weights?