I know that brake fluid can be very bad for a lot of parts on a car, but on all-metal situations where there is no risk of getting it on rubber, etc. I have used it quite successfully on nuts/bolts using a small syringe to place just enough to get the job done without spreading the stuff everywhere. I have tried other things on rusted bolts on farm equipment, and none have worked as well or as quick as brakefluid. Then once the bolts are out, I spray them off with brake cleaner to remove the brake fluid. Has anyone else ever heard of using brake fluid on frozen nuts/bolts? An old mechanic told be about it to get out a couple of frozen bolts that nothing else would brake loose. Within 45 minutes, it was out and I have used it on others where there seemed to be no chance, they all came out with no problems after one or two applications of the stuff (have to be careful where you get it though). All of my exhaust manifold nuts/bolts were removed yesterday using the stuff. Anything else I should know about this? Thanks for all the input you have given me, and your patience.. have a great day