My two cents worth on brake bleeding systems. (I haven't been following this thread so I hope I'm not repeating anything.)

 

1. I have used vacuum systems attached to the wheel cylinder bleed screw for years. The advantage of this approach is that vacuum makes the bubbles bigger so they are more easily drawn out of the system and bleeding is a one man operation. The disadvantage is that air can be drawn in past the threads of the loosened bleed screw, giving the a false indication of air in the lines when there is none. The severity of this problem varies from wheel to wheel and can sometimes be mitigated by wetting the base of the bleeder screw with brake fluid. (Resist the temptation to use oil or grease here as you could contaminate the system and the result could range from expensive to fatal)

 

2. The one man bleeders work fairly well but don't last very long. The downside is that they can suck a little air in past the bleed screw threads when you lift the brake pedal. In this case, you will always get one or two tiny bubbles in the hose no matter how long you pump the system. If so, you can assume that there will be one or two bubbles in the wheel cylinder when you close the bleed screw, unless you have someone hold the pedal down while the screw is tightened.

 

3. The pressure pot system that forces fresh fluid into the master cylinder and out the open bleed screw has no path to allow air to get into the system during operation (assuming you keep enough fluid in the pressure pot). The downside is that the air bubbles shrink under pressure and become more difficult to remove. This is really only a problem on antilock brake systems.

 

4. A system that injects fluid under pressure through the wheel cylinder should probably work fine, but I have never used one.

 

Rob