Bleeding Master Cylinder

Bleeding or priming a Master is usually the first thing done prior to brake bleeding. Traped air left in the master "could" have you running in circles. Also doing it on a bench is EZer to contol then in the car. You will need a extra person of course.
I made up 2 extra fittings with 4" steel tubing for the outlets and then added 14" clear tubing to the steel tubing. These two outlet ends will go into a jar with about 1" of brake fluid.
Ensure the master is full and have someone "GENTLY" push the brake about 1-inch and hold it steady without pumping. This first opens of the valve to let fluid fill the rod cylinder and some air excape. You will notice (looking into the master) air bubbles coming to the surface. This could take some time. Repeat this a few times to ensure the rod cylinder has no air. Add more fluid if required. Next will be the pumping, however do it slowly or fluid will fly all over the place. Watch the clear tubes at the outlets to jar. When the fluid comes out clear and without any air your set. It's important to keep the master full and don't allow any air back into the rod clyinder or you will have to start all over again. The outlet have valves, so you shouldn't loose much fluid returning doing up the "real connections".
The remainder of the system brake bleeding is "the regular" method. KEEP the master full at all times and start bleeding the furthest rear brke first working to the closest. Use again a clear tube around the fitting and watch for air.
IMPORTANT...
Ensure your helper pumps up the system until it's firm and holds it. Crack the fitting and watch for air. As the peddle go's to the floor ensure your helper doesn't let up on the brake peddle until your fitting is closed or air will be sucked back into your system. Repeat until your satisfied no air is in the system.
PS New clear fluid showing at the fitting with no air is the plan..
Cheers.