sticking or frozen sliders is what your problem is. The slider allows the caliper to "float" and apply pressure eqaully to both sides of the rotor.
Here is the test: pry the piston back into its bore. Then take hold of the caliper, see if you can slide it back and forth far enough to make one pad touch the rotor , then the other way to make the other pad touch the rotor. If it doesnt move by hand easy enough to do that, then the sliders are frozen.
Also...lubricating the pad contact points, you know, where the pad touches it mount before the rotor is put on, is critical.
I have had some pads that fit the caliper mount area too tight. I have ground a little off of each end to help keep them loose enough to move freely.
Your problem is not a hose, or cheap chink calipers, but lack of servicing the sliders and caliper mount areas. I see it almost everytime I get a car in that a DIY er has put on brake pads. Trust me.