If you have a door that keeps closing on its own here's a quick and easy way to fix it.
Close the door and pull one of the hinge pins. Lay it on its side on a piece of wood
and with a hammer strike the center of the pin hard enough to bend it just slightly
then reinstall the pin. If the door still closes slowly, bend it a little more untill it stops.
However, an excesive bend could cause the hinge to squeak or make a grinding
sound. If so, raise the pin about an inch and place a drop or two of 3-In-One or
other lightweight oil on it.