Brake line problems.. I have a 2000 F250 with 21,000 miles. The rear brake steel lines are rotted through. I have new seen such rust like this. My truck has never seen winter and never driving in rain and is always under cover. I also have a 1980 pick up and that has no where near the rust this truck has. I am very disappointed and shocked. I am having a problem getting the brakes lines to stop leaking. I have changed all of the rear brake steel lines but when I attaches the new steel line to the original steel line coming off the master cylinder I can not get it to stop leaking. I am hopping somebody has some insight on the problem. Thanks for any help...

 

Did you use a line with the proper flare? Some of those were a "Bubble Flare" which will not work with a conventional "Double Flare" lines you buy at a parts store. The parts stores do have adapters however.