Has anyone ever tried using brake fluid as a penetrating oil? My experience has been very successful with dismounting old tires. I have my own bead breaker and usually mount my own tires, (I have a balancer as well and balance my own tires). Occasionally, especially when working on old farm machinery, I'll get a tire that is rusted onto the wheel making it very difficult if not impossible to break the bead. What I'll do is lay the tire on it's side and pour a small amount of brake fluid around the bead and let it sit for a few days. Then I'll flip the tire and do the same on the other side. The bead will then break with practically no trouble at all and very little effort. While I know this works as I have done it for years, I don't know why it works. Does anyone have any idea why brake fluid works so well when other things, (old oil, diesel fuel, WD-40) won't even touch it?