Hi,
I used blue divel for my civic 04 because it was overflow from expansion tank, 3 month later I had saver leak from water pump side, the next day i took it to mechanic to check it, but it stop leak suddenly with no heat. 3 days now.
How could I know what's wrong?
thank you in advance

 

I don't know why this is so hard to understand...

What I think you're saying is that the coolant tank was empty so you filled it and now it's randomly leaking from the water pump? But the water pump is inside the timing belt cover, not sure how you would be able to verify that.

Replace water pump gasket, flush coolant is my recommendation, if I got that right.