I need some help deciding how to fix a problem. Years ago when somebody installed a sump pump in this house, they just knocked a hole in the foundation wall and ran a 1.5 in ID hose through it. The hole is under a set of concrete steps so I can't get to the exterior without someone to lift off something like a 3ft x 3ft concrete slab. When it rains hard, the water pours in as near as I can tell around the hose - a lot of water. The cellar where the sump pump is is irregular but at least 15 ft sq, and the other night it was filling at least an inch per hour. The irony: if I didn't have a sump pump I probably wouldn't need a sump pump. I just lifted the pump out of the muck today - it wouldn't pump the other night but the motor works, so I'll clean it and see what happens. I installed a check valve that it was missing, but the old discharge hose broke while I was gone - apparently old and brittle despite appearances. That part is a no brainer to fix.
The important thing is trying to do something about the leak. First issue is I have to work on the inside which is not the correct side. Second is the concrete block is never going to dry out - it's 90%+ humidity down there. What are the chances of using backer rod and the concrete/mortar sealant that comes in a tube - is there a better way to start out? And will Flex Seal adhere to damp concrete block, or is that a waste of time? I was thinking about the first two to fill the gap and flex seal over it. Am I wasting my time?