Braking issues

I do not know what brake pads you have installed but the pad/lining composition can have a very big impact on brake performance. Inexpensive pads/linings are just that. Inexpensive. I have played with brake compounds for years and have talked with a number of pad material engineers during those years and there are tons of variables in getting the performance you need. In drag racing you need a pad that simulates a "soft" pad, good cold performance, on the starting line to hold the car and yet a pad that needs to be able to reach maximum stopping force when applied cold at the top end but still have consistent brake modulation as the temp spikes from a 180mph application. This is a lot to ask of any brake pad/lining. There were "performance" pads on the market in the 80's that everyone used, but me, that would not stop a car and had the feeling of air in the lines. You could actually feel the first stage of the M/C hit the retaining pin for the second stage in the M/C. I recently replaced the front GreenStuff pads in my Santa Fe with an mid range priced ceramic pad and it does not stop near as well as before but it only goes 5 miles to the boat ramp so this is not an issue. Your problem can be fixed rather simply but first it needs to be diagnosed by a professional before someone gets hurt.
Randy