I have a 91 cummins and it is leaking in at the front of the motor. Now I haven't climbed under it to look yet but I figured I would ask what were the most common places that leaked before I climbed under it. Anything will help. Thank you

 

Take your pick,
Front crank seal,
Injection pump gasket
vacuum pump gasket
timing case gaskets
oil filter/cooler gaskets
oil pan
timing case oil fill point
engine oil or power steering oil?