I have a fluid leak from the water pump. I've looked from under the car and under the pump wheel (where runs the belt) there is a hole where the fluid comes out.

I think that there must be a screw in that place, does someone know wich type of screw it Is?

And if there isn't supposed to be any screw, what should i use to fill the hole?

sorry that I can't explain better, I'll take a photo as soon as possible!

Pretty sure if water is leaking from the water-pump body then a new pump is required.

If leak appears to come from rear of pump, then it's possible it's the water-pump gasket where pump meets engine block.

Good luck.

If the leak is from a hole in the pump casing, you need a new pump. Similarly if it's actually from the hole that the shaft passes through between the drive pulley and the impellor.

As above, if it's from the back face, it's probably a broken gasket, which can be replaced without replacing the pump.