Stop The Leak Fast!
Before you add a clamp, add a block of wood.
If you're in a hurry and don't have the proper tools, you can improvise by placing a block of wood over the piece of rubber before tightening a clamp. The block of wood will help to spread the pressure and keep the pipe from collapsing.
Obtain a C-Clamp
For a temporary remedy, place a C-clamp over the block of wood and a piece of rubber to plug the leak.
Remove the faulty pipe.
If you're more experienced with plumbing repairs, you might go ahead and cut out the damaged section of the pipe. Turn off the main water supply valve, empty the damaged water line, and cut out a length of pipe that extends about 1 in. on each side of the leak with a pipe cutter. Begin by securely grasping the pipe in the cutter's jaws and tightening the cutter's screw. As you tighten the screw handle, rotate the cutter in the direction illustrated until the pipe snaps.