coolant leak

I have a coolant leak some where around my water pump. Thinking my water pump was leaking because I have 91,000 miles on the truck. I changed water pump and T-stat, but with no luck and I'm unable to locate the leak.

However, I do think the leak is mainly around my time chain cover when I investigated futher. Normally I'd take it to a local Mechanic, but I live overseas and I have to double the cost to get anything fixed so What would be the best thing to do?

either replace the timing cover gasket or add some stop leak and follow the instructions it does work