Q: Coolant leak fix

If you are using stop leak, you will want to pour it into the radiator, which is the same place that you would pour the coolant in. This is how the stop leak will be introduced into the cooling system. In order to fix a coolant leak properly, I would recommend having the part that is leaking replaced by a qualifed professional. Common sources of leaks include the radiator, water pump, gaskets, and hoses. I would recommend having all of these parts inspected for leaks while the vehicles cooling system is under pressure to determine where the exact cause of the leak is.