since the leaking has been identified. I would pull more dirt from the leaking wall and install some building paper, tar paper, or flashing to assist in keeping water out. Then back fill sand at first against the wall, then come in with your rich dirt. Add some dirt, then water in, you want the dirt to melt down and pack it in. I would create a 35 degree dirt packing around the area so water will shed and go away from the foundation. I would do this all around the home.
Do you not have guttering? This could assist you also. Remember the concept, every home should be built upon its own hill all around. This will shed the water away from the foundation and save you headaches.
If you should use the tar paper idea, which its very very cheap, think about the overlap of the paper, the laps should be downward where water will not get in. Start at the bottom and then add to that overlaping 1/3 on each run.