hi all im going to use vcds to try bleed my brakes, i can not bleed the m/c because 1 of the nipples is broken off, i changed a caliper and lost loads off fluid, and now after a power bleed the pedal is still spongy, i know it can be bleed like this as a garage did it with vcds a few months ago and it hade the same broken nipple,my question are, do i need all 4 wheeles jacked up or just the front ? do i ezzebleed at the same time ?anything elese i need to no? thanks in advance.