whats wrong with my 91 honda crx brakes?

[Jake O]

i have tried bleeding my brakes numerous times.two of them wont leak any fluid no matter how much i pump, so i cracked the brake line and pushed the brake and have plenty of fluid going to the caliper but nothing coming out.so i pulled the caliper off and i can blow through the caliper with no prbolem.am i supposed to be able to blow through it that easy.if i can blow through them then y cant i get fluid through them.i done this to the front left wheel.but the right back wheel wont get any fuid out either.i didnt pull that caliper off yet.this all started by changing my rear brakes and now i cant bleed them.help