Well, I did the job. It took me 3 painful days of part time work. The convoluted way that dash is assembled is a disgrace!
I used a brass/copper heater core instead of the aluminum original unit. From what I can tell, there was no corrosion in the old one. It looked like the leak was coming from a seam near the bottom. I cut the unit apart and it was spotless inside. I probably should have used radiator stop leak!!!
By the way, I changed my coolant every year and used distilled water. My dads 1980 Ford heater core failed after 3.5 years, his 1983 failed after 2 years, his 1992 failed after 5 years, my 1998 failed after 4.75 years. Ford, WAKE UP, either put in a robust core or make access easy!
In any case, for those who want to do this one yourself, be prepared to spend time locating hidden, difficult to remove screws. I cannot believe Ford builds a product like this. The thought process that went into that dash assy is pathetic by current engineering standards. I have never worked on a more poorly built automotive product.
It is items like this that make Toyota a leading company the world over. Not that you will ever need to access a Toyota heater core, but if you had to, you could, and quite easily I might add.
I love driving my F150, however Ford has not learned from previous mistakes. When Nissan or Toyota comes out with a true competitor with similar interior room, count me as a previous Ford customer.
2009 SuperCrew Lariat 4x4 5.4L 6 speed auto.