How do I fix U brakes? I found an old bmx in my shed and I'm just doing it up a little as a good muck around bike. It's not very good, I don't even know the brand but i cut the front brake off, because it didn't even work but the back brake is a U brake but I've found that when biking I'll pull the lever all the way back (as far and the grip) but it's like the brake isn't even working.. I know it's working but it's just not strong enough. So I have 2 questions.


How do I make the brake lever harder to pull so I don't pull it all the way to the grip?
How do I adjust the actual U brake to be a little closer to the rim? 


Any help is appreciated! Just trying to get it working. Feel free to ask any questions too. 
Cheers!
There are 2 screws you can see at right side of the brake. the bottom one is just above the pad screw - it's one that holding the cable. Open it a little.
Check if the cable is going smooth (if not, you should oil the cable or even replace the cable, and maybe the housing too). Check the pads, that they are not wear, nor dried on sun.
Then pull the cable (be sure that the cable going well at the lever), push the pads up to the wheel from both sides (to add tension), and tighten the bolt. The upper screw is to add more tension if needed.