coolant issues

[jeff]

at first my 97 cav would hold water but lose it because the fan didnt work and the water was evaporating out
until recently i could get by with just adding water every time i drove

just recently it got to the point where as i pured in the water it just drained out at the same rate

my neighbor said the water pump is leaking but now the leak stopped and went back to how it was before

before i go through a costly repair does anyone know if it might be something else

and if it is the pump should i go ahead and change the timing belt as well?
my car has something like 127thousand miles
i hear the belt goes after 100?

[Mark]

If your going to do the water pump, It is never a bad idea to do the timing belt too.