I disagree. The whole point is TO run the master cylinder through the full range of motion, and to push any crud out--that is part of the reason you bleed the brakes. Since you should regularly change your brake fluid, it should never get so bad in there that you would tear out any seals. I find the fact that it exercises the full range of travel to be a + not a -.

As for pressure bleeders, I am still uncertain about them. I HATE Vac. bleeders, as I can never get a good air free bleed with them. However, my expereince with pressure bleeders is much more limited, but I know of more than one person who has cracked a master cylinder Res. trying to crank the pressure cap down super tight to avoid leaks. I know you do not need to do that, but people do it anyway.

I have bled everything from my MB to my race car to my antique truck using the "pump" method, and never had a problem. Maybe it's just me...I am a stick with what has worked for me type.