text: I imagine the cause of the problem was overfilling. Shoving new pads in a system bled for 80% worn ones will definitely result in overfilling.
  I cleaned it up and rotated the steel gasket with a screwdriver (picture 2) until all the dirt got untrapped. It's working fine now, just needs an oil top up. Thank you!
  The leaking point is seen on the 2nd picture. The truth is it was really dirty before i took the picture