I changed my heater core (97 F-150 4.6 L) this weekend. Probably took me about 7 or 8 hours total. Before I get started, I think there should be a big memorial wall with a big painted middle finger in the lobby of the Ford truck engineering headquarters. It should read "We changed your heater core. If we have to do it again, we're kidnapping you guys to do it." And all of us who have done this should be given a chance to go there and sign that wall.






Now here are some practical observations and recommendations for the next guy while they're fresh on my mind.

• This 3 part video is great. F150 Heater Core part 1 - YouTube I also used that 21-page instruction file that can be found on various threads, but it seemed to describe a lot of extra electrical disconnections that would be needed if one truly removed the dash COMPLETELY from the firewall. I removed my dash to the same extent as the guy in the video.
• Change the blend door. PERIOD. No exception. Mine was already cracked.
• Go to Autozone and rent the heater hose removal tool, and buy two of the replacement Dorman heater hose ends shown in the video (he clearly shows you the part numbers of the blend door and those hose ends in the video). Rob the internal parts from the replacement hose ends and use them on the original heater hose ends (just like the guy does in the video). The heater hose removal tool isn't perfect, but it will work if you fiddle with it for a few minutes.
• Get a 7 mm nut driver (trust me). Otherwise, have a good set of small metric sockets and a screwdriver-type socket driver in addition to the ratchet. (Amazingly, you won't need a single phillips screwdriver, and you will only use a flat screwdriver to pry off some plastic pieces)
• Get a flexible magnetic pickup tool.
• I used a small plastic organizer for all the parts like the guy in the video--hands down the best piece of advice he gives.
• Definitely get the foam piece to go around the heater core. If your parts store doesn't have it in the box, stop by a hardware store and get some stick-on weather stripping of the same thickness.
• Don't be afraid of the fact that you need to drop the steering column. It's not a big deal. Just don't forget to unhook the shift indicator wire before you drop it.
• Before you get started, park the truck in a garage or shed so that a ceiling light is directly over the windshield--will make a world of difference.
• Wear a long-sleeve shirt or some of those forearm protectors. My forearms are tore all to hell from the sharp plastic edges and corners.
• Tell your buddies and any other potential helpers to go home before you start. In my opinion, it's a one-man job. Otherwise, you'll drive each other crazy and probably want to shoot each other before it's over (you can get the dash away from the firewall by yourself).
• DON'T drop the airbag after you remove it.
• Once you get the lid back on the box containing the new heater core, you're home free. It doesn't take very long at all to get the dash put back together.

Good luck! YOU CAN DO IT!!!

 

Nice tips. I recall doing mine years ago. Although it isn't horrible I just kept thinking there is no reason this needs to take so long. I'm sure I could do another one much quicker, but it also took me about 8 hours.

 

I also agree that I could do a second one much quicker because I now know what exactly has to be taken loose (and what can be left alone). Even with the instructions and that video, I still had to "study" it a lot to figure out the next move. I think one of the most ironic things about the whole job is the fact that the glovebox door doesn't even have to be removed (just opened wide enough for access to some screws behind it).

 

I was helping out a friend with his 1997 F150. What a mess. I think this truck was a Katrina flood truck. Never seen so much rust! Anyway he brought it over and then left it - told him would be a while. Went to start it after a couple days and it would crank and not start.
After running the wiring for shorts and having to replace a megafuse holder, the ultimate culprit was one of the noise suppression electrical connectors on the intake manifold which had fallen off (the plastic cover was missing) and eventually grounded to the manifold and was blowing fuse 33 in cab. So now the truck was running again.
This truck had been blowing the 5 fuse in cab as well. Pulled the usual suspects other than the blend door motor connection and was still blowing the fuse. Finally while doing the heater core replacement using the excellent instructions on the FTE site, pulled the blend door and then unbolted the motor and it was burned up. Looks like it tried to catch fire. When attempting to release the electrical connector, the motor side came with it. Getting the motor out - what a pain.
My son is studying to be an engineer and I told him that engineers should be forced to actually work on what they build.
Got the mess all back together with a bone-yard connector for the blend motor and all is well.
Had the steering column out to look at a shifter problem - hard to move AT column shift. The cable was broken - replaced with bone-yard part. Problem appears to in the trans. Most likely the one piece braised shift lever which is REALLY RUSTED. Didn't tackle that as the bolts on the attached switch will most likely break, then I'd be pulling the trans to heli-coil the sucker.

 

Thanks Doc. The tips you gave and the video really helped.
Took me 8 hours. I changed the core and the blend door. I say TO HELL WITH THOSE QUICK DISCONNECTORS ON THE HEATER HOSE. Mine broke as I took them off so I just cut them off and just used hose clamps. Works like a charm now.
Doc, if Ford ever puts that sign up, let me know. I'll sign it. What a P.I.T.A!!!!

 

I did mine last fall.2002 f150..yes it was time consuming,but not hard...as for the hose connectors,i waited till i had the core opened up and just cut the tubes off core and pulled thru firewall and then disconnected hoses,a lot easier than using tool up under that firewall lip.