how do you know its coming from the overflow?or can you see its all wet under the expansion tank? the only pipe apart from the one out the bottom is the one from the top that helps with bleeding. theres a tiny little bit of pipe that goes from the back of the cylinder head at the gearbox end. its behind the vacum pump and that likes to split and be sneaky and loose water. do you get anything else happen like hard water pipes, airlocks, rough running or anythign?
