Found a Crack is it a stress fracture or metal fatigue?

I dont mean to taking over with posts but I got some time to correct a few problems. When I took the larger cover plate on the rear housing off I found this crack in the front coner where the spring hanger attaches for brake petal. Haven't found the end yet. Just curious if its a major fix asap kind of problem. Cant post pic from phone will try later from computer. Thanks

Are you referring to the brake return spring anchor bolt with the crack radiating from the large cover plate opening to the bolt? If so that's probably a stress crack. Don't know that I'd get to excited about it, just make sure it's sealed up so that it doesn't become a water leak source. The housing is fabricated steel so welding it up would not be a big deal if you choose. Probably a good idea to find the end of the crack and stop drill it if it goes beyond the anchor bolt hole.