is there a way to tell if it is messed up

any other ideas as to what may be the problem

Yes, a new master cylinder can pump to all four brakes and still be defective.

But let's hope it's not that.

ok thanks thats the valve => splitter thing i meant and as for broken master cylinder this one works because itll pump to all wheels and i already had a new one i just bought die a few months ago which sucked and the rear brakes i did adjust that square peg thing with the handbrake off and ill try with the tube into brake fluid

Yes, either the new Master Cylinder is defective or you still have air in the lines.

Bleed the brakes uses a line into a glass of brake fluid so that no air can be sucked back in. Bleed the left rear wheel first, the right rear. Then do the left front and finally right front.

Do not forget to manually adjust the rear brakes by turning the 1/4" stud.

BTW, B210 has no proportioning valve, but it does have a splitter with built-in pressure sensor.

sounds like air in the system still bt are the rear shoes adjusted correctly(ie did you adjust them with the handbrake off)

im no brake expert, i hate working on them

I'm trying to fix my b210 and I have replaced the master brake cylinder, the calipers, the shoes,had the drums turned, and had the proportional valve and one other odd one thats right next to it that directs flow of liquid redone. I also bench bled the master cylinder and bled the whole system. It will brake if you push it to the floor but its really loose and doesn't brake to strongly. Sometimes though, if you pump it then it will firm up and brake well. NOT SURE PLEASE HELP! THANKS