Antifreeze leak on front

[weberj62]

Hello all straight to the point. I have a antifreeze leak on the front of the motor. Changed the water pump. I cleaned every surface that had contact with the o rings. Also all new o ring on every fitting. So once the motor cools down there is a light leak working it way down the front of the motor. It can't figure out where it's coming from. It only leaks when it cools down, it's only small amounts. Any thoughts

Thanks