I'm re-doing the rear brakes and I noticed that one of the short rubber brake lines that connects the rear caliper to the fixed position metal brake line is cracked.

There's no evidence of a leak but the car has over 100k miles and I thought I would replace it for safety sake.

I have the new rubber line but I'm finding it very difficult to get the old one off where it connects to the fixed metal line. There is kind of c-shaped spring washer between the brass male line fitting and the metal female rubber line fitting. When I try to loosen the two fittings, it just strips the brass nut.

Is there a better way to do this? I don't want to strip the brass nut so bad I have to replace the entire metal brake line!

Thanks,

RGW