How do you fix a leaking foundation wall depends on the type of base material what is built? Masonry and concrete in most cases can be quickly and easily patched. stone foundations often require extensive repair or replacement. small cracks in the stone base is often the case of residential land or shifting earth, too fast drying of the mortar between the courses of blocks when installed and even excessive soil moisture can provide sufficient pressure on the exterior to break the wall.
First check the interior and exterior of the foundation walls to see if there is a physical reason cracked wall. You can also hire a qualified contractor for foundation waterproofing via https://americanwi.com/settling-basements-foundations/
If the earth along the foundation has sunken because of missing downspout leader adds tons of water against the foundation or class may have been changed without anyone realizing that rain water is now flowing against the building.
Stagnant water can be super saturated ground caused them to drown and thousands of pounds of pressure to exert on adjacent objects such as foundation walls.
Because the basement back filled only on one side and an open-air space inside, hydraulic ground pressure can be easily cracked stone walls and possibly with a solid concrete foundation crack as well.
Your first action should be to correct this problem by re-grading or other work required to ensure all runs water from the foundation. When finished, turn your attention to the foundation itself.