Mercury Repair Questions? Ask a Mechanic for Answers ASAP
Hello and thank you for your question,The tubes at the firewall that the heater hose connect to are part of the heater core. You may want to start first with making sure its not just a bad heater hose leaking at the connection . If the hoses and the connection check okay and the leak is in fact coming from the tube then this indicates a bad heater core.
It sure is possible, if it is then it will be coming off of the outlet tube that the heater hose connects to on the manifold. Your going to need to clean it off and see if you can pinpoint it. The manifold is the most common source of a leak in this area for sure.