Quote Originally Posted by ojh View Post
If you think about it, it would make perfect sense that both (all three?) lines would go out at the same time, because whatever affected one line would affect the others as well. I'll admit the possibility small since the fluid is DOT 3. At this point I'd sacrifice a brake line and cut it in half to see if it has swollen, I had one last month that I couldn't stick a tig welding rod thru. You've changed all but the concrete the car is sitting on, not much else it can be. Just let us know, ok?
Do what ojh says, and sacrifice one line to eliminate them from the equation. If you find it swollen and restricting change them all, but also consider that you may have a contaminated system, and if you do every rubber component is going to be suspect for failure. Is it possible that your Dad purged the system and used DOT 5 fluid when he did the earlier brake work?