My brake is mushy and goes close to floor before stopping i also hear the sound of air being released when pushing brakes
Could be a bad MC, but another explanation for those symptoms is air remains in the brake hydraulics and/or thereās a problem with the brake power booster. Another possibility is thereās a problem with the ABS system, assuming your Kia has ABS. When replacing pads the caliper piston has to be retracted, and the usual recommendation here is to take precautions ā open the bleeder screw etc ā so that brake fluid isnāt pushed backwards into the ABS system.