There is no break in time. Make sure your using oem mitsu parts. When you install it make sure the crank is not nic'd. Also when you install it you need to make sure the spring on the inside on the seal stays on there you just need to have patience. If you cant do it ask a shop to do it.

Did you make sure the leak ant coming from anywhere else?

If a seal was leaking too long, the teflon compound that the seal is made of gets all rock hard and can actually cut a fine groove in the crank where, outside of a crank milling or replacement, no new seal will cure the leak.

...been there and done that to know about this and it really sucks when one finds out.

Good luck-DSM

Im sure its the crank seal again. The timing belt has a very small line of oil on it. I think I know why its leaking again, my dumbass was in a rush and doing it outside in like 0 degree weather and I didnt apply oil to the seal before putting it in. Yes I know the crank could be scored but Ill replace it once more the correct way(since i have a shop to work in now)and hope it dont leak again