About your leaky tires -- I do not know (and you might not either without looking) whether your front wheels are two piece or not. I had a situation with an older Kubota B2150 where I had a chronic leak on one front tire that I just could not solve. Had me baffled. Finally found out that the wheels are two piece and (if you have tubeless tires in place) the two halves of the wheel can leak air between them. Of course tubes are the best solution but one could also take the wheels apart, buff the two wheel halves' surfaces where they mate and tighten them back together.