A Question about Brake Pressures / Flow

[JamesDean]

Morning everyone,

I installed a new master cylinder on my 190E last night. I bought a nice Napa master cylinder bleeding kit and while I was bleeding it I noticed that the side port (closest to the rear of the car) flows fluid at a earlier point in the pedal travel and the top port.

One had to go more than 1/2 pedal travel or so to get much fluid flow at all from the top port, while the side port flow nicely through all pedal travel.

This new master is properly paired with the booster. Both are E420/E500 units so I know the push rod inside the booster is the correct length.

My questions

Is that normal?

What calipers are fed by the side port? and top port?

What happens if I reverse the ports (assuming it were easily done)?

For years now I've been trying to figure out why my brakes take so much pedal travel to engage and grab well. I've been through many master cylinders and three different boosters, trying various things. Nothing has made a substantial difference.

This pass I am working my way top down making sure everything is as it would be if the car was a E420/E500. So as of right now I've got:

E420/E500 Booster (used)
E420/E500 Master (new)
E420 Front Calipers (rebuilt from NuGeon - 2/3 years old)
SL600 Rear Calipers (rebuilt from Centric - 1 year old)
Textar Pads
R1 Concepts Rotors (1 year old)