good question.... well i replaced everything except the water pump and thermostat when it was leaking.... after changing everything and we did a pressure test ... still could not detect leak with pressure test.... so my mechanic decided to keep the car overnite at his place and next morning , he notice leaking from the water pump as the floor had 2 puddles of water.... one from the aircond and another directly from water pump but was very very little.... changed the water pump and thermostat ..... wala , no more leak ..... since 6 months ago no need to add water.... still the stick is stiking out straight, bro..... but however u need to confirm there is no leak into the engine bro.... make sure cylinder head is in good condition..... Go to Albert Pang, Pandan Indah.... He is my main man, cheap , reliable and does not cheat bro.... Phone no. 0122017792.... mention my name ... u get good price bro.