Front heater core - Partie une

OK, as previously noted - my front heater core was clogged.  Now in my mind, if I am going to spend a couple days removing and replacing the dashboard, I will be damned if I am going to install a used part.

So given that the wife's CR-V was hit a couple weeks back and we will need to have it repaired, I cannot immediately tear apart the van as I will need it to get around.  The wife will take the S420 and I will look cool in the Thingamajigger.  The S420 is about 4 feet longer than her CR-V, so I am a bit afraid for its well being.  C'est la vie.

So to get a jump on the project, I procured a heater box from my NH friend Peter who has a few vanagons he is parting out.  The following is the rebuilding of the box to be ready for the tearout.  I have also ordered a new wiper motor for the simple reason of mental ease that I did it when the dash was out.  I am hoping that the wiper arms are in good shape and can be lubed and re-used.

This was the box just after tearing it down.  It was one of the glued versions, rather than the clipped ones.  The difference being about an hours more work in separating the box, and then another hour preparing the surfaces again for putting back together.  The clipped ones come right apart after removing the clips.

As you can see, the heater core is pretty well gunked up, and that's the outside.  The clog keeping it from flowing is internal, and probably removed with some CLR, but I am not taking the chance.

Here is the new core and the original.  The older one is of really good craftsmanship, and the newer one not as much but still good stuff - made by Behr in the UK.

So I started tearing it down, removing the pieces, the flaps, the motor.  Once the flaps were out, I contemplated how I would rebuild those.  I stripped off the old deteriorated foam seals and was left with this to work with.

I wire brushed the best I could and was not satisfied, so I broke out the spot blaster and spent way too much time cleaning these up.  I really need to buy a sandblast cabinet.

Once the flaps were rust free to my acceptance, I cleaned them up with some paint prep solvent and spray painted them with some black paint I had on the shelf.  I hung them above my propane heater to cure up real well and went to work on the box itself.  The box was really dirty, dried dust from many years of use, but no mouse nests.  A toothbrush, air gun and some dried rags took care of the dirt.  A final wipe with some simple green and we are ready to go.

I deliberated for a bit on which way to go with the seal material, and determined that the synthetic felt used for window insulation would do nicely. 

This stuff stretches out perfectly, seals up nice and should hold up long time.

A few correctly placed slits down the middle allowed for perfect alignment and a quick pass with the lighter cleaned up the edge strands.

After doing this to all three flappers, I was ready to rebuild.  Reversing the process for installation, the flappers went in with a slathering of grease (because I did sand blast the arms), and got them working beautifully.  Some new stainless screws to ensure no deterioration down the road, and some one sticky sided foam  (1/2 in by 1/2 in) stuck to the periphery of the heater core to seal the spaces around the core and prevent rattling.



The picture was taken prior to cleaning the box with Simple Green, to test the foams ability to seal the gaps around the core.  You can see the tabs that were previously glued and now separated.  I cleaned them with a dremel to ensure a correct fitment when reassembling.



The felt seal installed with the stock mount clip bars, and in the housing.

Next part - the installation of the blower motor and reassembly.