Installed a booster and cylinder re-ran new lines, the front brakes bleed fine but the back ones barley have fluid that runs out when i bleed em. Is this because the back are still drums using shoes and the lines are smaller or something else. I put rotors on the front and have no problem with fluid flowing to these. I also installed a proportion valve. I used all the parts from a 87 truck, the booster is working i tested it and the lines are ran to the correct parts of the master cylinder. thanks in advance.
