Good idea! True, if you are in a salt laden environment the steel fluid lines can seize in the valve or the fitting can seize to the steel line. Spraying the fittings with aerokroil or another rust penetranting oil a day in advance can help. Once this is done a quick slap on the proper line wrench rather than progressively applying torque will usually break the fitting free. If I suspect problems with rusted fittings I will frequently just go straight to using curved jaw vice grip brand locking pliers on the fitting. If used properly this procedure won't damage the fitting and will result in successfully loosening the fitting without rounding it off. Mark