Weak brake issues

[almostacrayon]

Hi y'all,

I'm having issues with the braking on my newest e30. I have so far done the followjng:
- changed the soft lines with stainless lines
- bled the system 2x (full flush with different colours to see that its fully through) fluid comes out as a decent flow so I don't think there is any blockages?
-tested the booster and it has vacuum doing the pedal pump to firm and hold test, turning on car and watching it sink a little.
- bought a new ate Master cylinder from fcp and tested that
- changed the pads and rotors with new blanks and bendix pads

there doesn't seem to be any leaks as the master cylinder reservoir is still sitting at full. When I push on the pedal to brake it slows down but very slowly, stamping on the pedal doesn't lock up the brakes, this is a poverty spec model so no abs.

I'm running out of ideas as to what it could be...

any help would be greatly appreciated

cheers,
crayon

[jbontke]

Does your car have ABS?

[roguetoaster]

I think it's a simple air lock, or water/crud buildup behind the pistons of the calipers. If you haven't already, I'd reseal/rebuild your calipers, which isn't overly difficult, and then bleed once more. Or, if you have or can borrow a pressure bleeder that tends to solve most stubborn soft pedal issues. Both solutions together would knock out any issues that aren't a blocked hard line.

[almostacrayon]

Sounds like a plan, will buy some rebuild kits and do all the calipers. Hoping that will solve it.
I have been using a pressure bleeder to bleed/flush the system but haven't noticed much of a difference though.