I have an 82 XV750 that has no pressure in the front brake lever. The previous owner had rebuilt the caliper thinking that was the issue but still couldn't get any pressure so he figured it was the master cylinder. Before I did anything to the MC I bled the brakes, got some air out but still no pressure. I have a second 82 xv750 with a working front brake so I took the MC off that one and installed it on the first bike. Even with a MC that I know is working, still no pressure to the lever. Doing some research I saw some people said that air can get trapped in the banjo bolt or in the line and that sometimes you need to bleed the brakes for a really long time before you get any pressure. The bike has 4800 miles on it and everything on it looks almost new and looks like the bike has been very well kept. The second bike that I got the MC from has 22000 miles on it and is in very poor condition, even the MC looks like its in rough shape but still works. Im starting to get the idea that theres actually nothing wrong with the MC and I just need to keep bleeding the brakes until i get pressure, but im not really sure. Everything looks so new on this bike that I'm having a hard time thinking it could be bad parts, but these bikes are almost 40 years old so who knows. I have a braided steel brake line on the way, would a bad rotor cause this? Im also thinking of swapping the caliper with the caliper on the second bike because I know that one is working. Anyone have any idea what this could be or where I should be looking? Any help would be greatly appreciated!