here is how you can find out by yourself if your problem is on the outside or inside--On a dry day get a hose and run it full blast on the outside of where you are leaking inside...lay the hose a couple inches away from the wall and let it run for a good hour or so. You are recreating a heavy rain against the wall from top to bottom...you may have to move the hose a few feet along the wall to left and right.If there is a crack or other opening through the wall you will begin to leak and so you now know part or all of your problem is the wall and you should fix it from OUTSIDE!.If you don`t leak after a good hour then take the hose and run the water against the bricks(may be open mortar joints) or against a basement window and work your way very slowly from the lowest points upward.Don`t soak too big of an area at a time,you want to be precise...if you begin to leak while running the water against brick or a window or a line that enters the home then THAT is your problem(opening) that is allowing water into your basement.But..if you still do not leak in basement after running the hose now for 1 1/2 - 2 hours...against everything on the outside(all the way up to roof) of where you are leaking inside...then your problem will probably be that on heavy rains/thaws water is being forced up at inside isolation joint or up through floor cracks and you will need a sump pump(s) and ONLY Possibly an inside method which will keep the water off your bsmt floor and control the level of water under the floor if installed properly.