I just got done replacing the master cylinder and pads and shoes on my rear drum brakes. But for some reason the brake line that goes into the master cylinder is not screwing in all the way? Its not leaking or anything it just wont go all the way in. You can still see some of the threads. I tired tightening with a wrench and the thing wont budge. My Friend helping me bleed the brake lines told me you don't want it to tight and you don't want it to loose. Has anyone else had this problem when it comes to replacing your rear cylinder?

 

There will be some threads left. It's not going to bottom in the hole. If it is tight, and doesn't leak, that's all ya want.