so theres a leak by the water pump pulley? what must be replace???

it leaks when theres pressure

heres a few pics

 

Looks like its time to replace the water pump

 

Agreed. Waterpump is on its way out. If you loosen the Serpentine belt and can wobble the fan up/down/left/right , the bearings in the pump have worn past their limit, causing coolant to leak through the pump and out of the weep hole on the underside of the waterpump.

Water pump comes out pretty easy, but the bypass hose is a pain in the *** to get to, and the fan clutch assembly can be problematic even if you have the right tools to take it out. Let me know if you need any help/pics of the install, i just did this replacement over the week end and it took me about 4 hours and a 12 pack of beer