bleeding brake master cylinder

[l1ttle_d3vil]

I'm still trying to sort my brake system out. I've installed new calipers after the last ones were leaking, bled the lines at each wheel but the pedal is still spongey, although it doesn't go right to the floor.
The car will stop, but just takes its time and the rear brakes are locking up too.

While the calipers were leaking the master cylinder resovoir was completely emptied of fluid - hence sucking air through.

Is it likely that the master cylinder itself will need bleeding, separately to the brake lines? I've read that this needs doing when installing a new cylinder to remove the air from it, so I'm guessing the same would apply for when the fluid has run out.

Also, is it a major issue if the proportionary/bias valve is fitted level or slightly above the master cylinder?

Cheers
-Matt

[hsmidy]

bleed the master cylinder and then bleed the bias valve, also if you have used the bake pedal while there was no fluid in there and its an old cylinder its not uncommon to stuff the seals on the master cylinder

[Crimson Tears]

Crack the brake pipes off at the master cylinder and undo them a few turns. Then fill your master cylinder with brake fluid. You should see brake fluid bubbling out around the threads of the brake pipes. When you get a constant drip of brake fluid around the brake pipes, tighten them back up and then give the entire brake system a thorough bleed. Remember you should start with LR, then RR, then LF, then RF.
As for the proportioning vale I don't think it would affect it.