In the event someone else comes across this thread while researching TSB 04-0212 regarding the leaking cooling system, I want to share my experience from today.
I just purchased a 2012 Mustang
last week with the 3.7 that has 59,000 miles on it. I noticed leaking coolant from the car and took it to my regular mechanic to look at it so he could tell me what was wrong in the event it wasn't covered under warranty, so I wouldn't have to pay my local dealer's $85 diagnostic fee. While he was looking at it he could not find the leak, but did notice some staining on the engine under the water pump indicating it had been leaking. Since my manual stated that the water pump was covered under the powertrain warranty, which is 5 years/60,000 miles, I took it to the dealer. They did confirm that it was a leaking water pump; however they said that only the water pump, br3z8501g was covered under the warranty. They also had to replace the hose er3z8276a and seal 7t4z8590 (per the TSB I found out after my research). They only charged me for the parts, no labor since they did not call me prior to doing the work. Even if they had called, I would have probably argued against having to pay any labor for installing those parts since they would have to be removed and reinstalled when replacing the water pump anyway. So, I came out paying $45.22 in parts. I was glad it happened before the powertrain warranty ran out!