What am I missing here

[FLYNAVY53]

Why is it that when I bench bleed my master cylinder, I get full throw of the piston....when I bleed the rear calipers with the master cylinder installed, I get full travel on the brake pedal...but when I try to bleed the front calipers, I only get half the travel on the brake pedal, and I'm only pushing half the volume of fluid per stroke as I am when bleeding the rears?

Lines and calipers are all brand new. I pulled the master back off the car to replicate on the bench. With the rear port open and the front closed (simulating bleeding the rears), I get full throw on the piston. With the front port open and the rear closed (simulating bleeding the fronts), I can only push the piston half as far.

Any help would be greatly appreciated!



Greg