That is not a bleeder. It is a special hollow bolt that is an air vent for the axle housing. Yes it holds the T fitting to the axle but otherwise it is not involved with the brakes.Say, that t on the axle has a big ole bleeder that more or less holds the t to the axle. If it doesnt bleed the t, why is it there?
In simple terms, (Not using real numbers). If the total stroke is two inches (1 inch for front, an 1 for rear). If one side is bled (no air), the most stroke you will get is the 1 inch when you open the rear line. Under ideal conditions, the brake pedal will hit the floor just after the total stroke. That way if one end leaks, you still have the full stroke of the other end. So ideally, you should out stroke the master before you hit the floor (ideally, not real world). Also, ideally you are not using the full stroke to bleed the brakes, that way you are not hitting the end of the stroke inside the master.So i understand the front and rear are separated at the master. If the front system is totally closed how could the front "catch" when doing rears and vice-versa? At any rate today or tomorrow im taking the drums off to inspect anyway.
When I do a full brake job, I will use a piece of tubing, and hook it up after I finish a corner, then just leave it open to gravity bleed while I do the next corner, while watching the master level. I go through more brake fluid that way, but it generally needs flushed anyway. By the time I ma done, it generally does not take much bleeding.I made a bleeder out of a mason jar and surgical tubing. Then I go in and pump the brakes until I don't see any more air in the surgical tube.