I just replaced my evaporator and heater cores, and if you frequent f150 message boards, you probably saw my posts asking how to get the freakin evap core out. Got a few pointers from some folks, and finally figured it out.

I'm not saying this is the proper, by the manual way to do it. But it did the trick for me. This may not remove the entire plenum, but it certainly made it loose enough to pull it away from the firewall, and I thought I could've pulled it all the way off if I wanted to.

First, if you haven't already taken the dash out, do a search for replacing your heater core, and there's an amazing write-up in a Word document on how to do it. Once you've got the dash out, hoses disconnected, and plenum cover removed, try this.

Most of these pics I took after I'd already disconnected them, so I apologize that it doesn't match exactly what you'll see.

Step 1: Remove this nut in between the holes in the firewall in the engine bay where the evaporator and heater cores connect. I think it's 10mm, could be 11mm. A flashlight helps to see it.


Step 2: Remove your battery completely, as this one is kinda tough to get to with it in there. Possible? Yes. But difficult. Standing at the passenger fender, looking at the battery, there is the same sort of screw as Step 1 located on the firewall in the engine bay, directly left of the negative terminal on the battery. There are actually TWO nuts on this screw. The top nut holds the accumulator brace and AC hose. Remove that and you'll discover a nut that looks identical to the one in Step 1.


Step 3: In the cab, remove the nut that's above the blower motor (passenger side), connected to the frame that goes across the entire dash. It's right above a vent at the very top of the entire plenum box.


Step 4: Underneath and to the left of the part of the plenum where the heater core is (right where the evaporator drains out, there's hidden nut. I actually found it with my hand before I saw it. There's a little room just down and left of the heater core where if you contort your body like a circus freak, you can see the bolt.


Step 5: There's a brace that kinda holds up the plenum, pretty much right beside Step 4, and it runs all the way to the front of the plenum (like the plenum is just sitting on this brace). It's connected to the frame on the center hump. Pull the carpet or flooring back, and you'll see the two bolts that connects it.


Step 6: On the driver side of the center hump, there's another brace, but the bolt is connected to the plenum. There's also a little small dowel that kinda lines the brace up on the plenum, so once you remove the bolt, be aware of that. I don't have a good pic of this, as I'd already put most of my dash back on, but here's the location.


This is my old evaporator core. Looks nice, huh.




I hope this helps some folks out. I've asked (and continue to ask) so many questions here, and you guys are awfully helpful. Just trying to do my part. Let me know if I've left something out.

 

Thanks for the pics. I will do this today. Did you have to remove the heater core and the entire a/c box housing to install the evaporator core or can I just slightly pull a/c box housing out just a bit and be able to remove and install the evaporator core?

 

Well, I'm not really sure if it'll pull out with the heater core still attached. I doubt it will. I went ahead and changed my heater core while I was in there, as I didn't want to have to do this again, an heater cores aren't very expensive (at least from Rock Auto).

 

Great write-up. It will definitely come in handy. Probably for more people than you realize lol.

 

I removed and replaced my evaporator core by just removing the nuts/bolts and pulling the evaporatore/heater core housing back out a little bit without having to disconnect the heater hoses. Again, thank you for all your help with the write-ups!

 

Could you walk me through that in a little better detail. I have a 97 F-150 and I think that the evap core is clogged up -- I have had the compressor, clutch, accumulator, and orifice tube replaced, but the A/C will not blow hard. It will blow cold air, just without enough force to cool the interior off. The blower motor sounds like it is running fine, but I will check on that tomorrow.
If there is a way to access the evap core, without taking the dash off completely, I would like to do it that way.
Thanks in advance

 

I appreciate the description and pics for the evaporator core; I too was about to cut the tubes to get it out but knew there would be no way to get the new one in.

The gasket in front of the core is no longer available from Ford, so I had to improvise - top and sides was OK but bottom piece was shot.

I did a video to add to what RealFixesRealFast had in his 3 video series and added pics of my own with links to other resources, tools etc.

http://pcroger.com/1998-ford-f150-he...p-information/

Best,
Roger.

 

03 Ford f150
I been wondering the same thing. replacing both heater core & evaporator coil. lot on there about the heater core. gonna tackle it tomorrow. get back with my input. TKS for pic and write up. should help alot.

 

As was mentioned before, this is the first of a 3 part video showing how to replace the heater core and blend door.