A few months ago, I wrote an article about repairing the heater valve bracket. You can see that article by clicking here. I really thank all of you for reading and all the responses received from the 2002 community. I had a tremendous request on the parts that I designed. Therefore, I decided to make some improvements to the bracket as well as additional parts that make rebuilding the heater box easier.
I have gathered and made some special components/parts for those who want to rebuild the box themselves, starting with a new design heater valve bracket. I was fortunate enough to find a heater box top with an intact bracket. I was able to follow the shape of the original bracket, and because of that, the new design will be almost identical to the original bracket. The kit will also available with the other following items:
• Heater valve lever with pinch bolt
• Rubber grommets and delrin bushings (custom made)
• Pre-cut foam kit for the flaps, heater core and perimeter box seals
• Heater motor with a new fan blade
Those who are interested in the parts can contact me at email@example.com.
This is the picture for the foam & grommet kit. On the left are foam strips for the perimeter box seal (furthest left), and then the heater core seal. In the upper middle area is the foam for the defroster and heater air flaps. Underneath that are two big rings for the heater core outlet. Below that are the flap grommets (the 7 small circular ones). Beneath that is the four relay shaft delrin bushings for the defroster and heater flaps. Beneath that is four spring clips that also go onto the flap shafts. To the right of that is the foam for the fresh air flap. To the furthest right is the foam for the outer box.
Version 2 of my heater bracket reinforcement! I’ve updated it so that it looks very similar to the original bracket that was created from the factory. This time, the bracket is made in aluminum, making it lighter than the previous version.
If your heater fan motor is seized or making noise, you don’t need to worry. I will show you how to get a replacement parts or you can get it from me. The heater fan motor is still available from Bosch, part # 0 130 007 002. The fan motor comes with a 6 mm shaft, or just slightly under ¼ “. If you buy a ready made fan blade with a ¼“ bore, it will be loose. The only option is to buy a plastic fan blade from Grainger, part # 5JLL6. It should be 5-9/16” Dia, CCW, with a 3/16” bore.
This is the closest fan blade to the original aluminum fan blade, except that it is made of plastic and is lighter. Enlarge the bore with a 15/64” drill bit, but make sure that you drill it straight and on center, otherwise it will end up having a wobble (slight wobble is acceptable). I made a special jig to perform this job, since I do quite a bit of these repairs. Once the fan blade is done, press fit it onto the shaft with the clip facing away from the motor, and if you want, you can drop a little glue to make it more secure. You don’t need to balance it, since the blade is so light. It should provide you with plenty of CFM - I think it blows slightly stronger than the original motor. See the pictures below.
These images show how I align the fan so that I can drill the fan perfectly centered.
The grommets for the heater core outlets are very difficult to acquire. Even though the part is still being made by BMW, they are not available unless someone has old stock (NOS). Most of these grommets are dry, brittle, and torn after 30+ years. You can use sealer or putty to keep it together and seal the box from leaking out air, but it won’t look pretty. I found a replacement heater core outlet grommets (¾”x1/4”x1-⅝”) that were very similar/ acceptable to the original ones, and with slight modification, it would look like almost an oem part (see pictures). The rest of the parts are straightforward, except for the fan blade which was a little bit tricky to do. If you look at the pictures below. I put together a kit for what is necessary to rebuilt the heater box. This is the same kit I use to rebuild heater boxes.
These are the grommets for the heater core outlets. The white area is where it is going to be trimmed - Without trimming this, the grommet won’t fit. It would need to be cut ⅜“ from the inside diameter. What you should get is this:
You should fit it onto the box with the flat side facing to the outside of the box, as shown. But from here, there is still some further modifications that need to be done. Unless you cut out a groove for the pipes, you will have a hard time putting the top cover onto the assembly. This is why I modified the grommets, grind the inside diameter following the outlet heater core pipes by using a die grinder or round file. It should be approximately ground at 30º - 45º. Both the top and bottom of the grommet will need to be cut, but on the opposite sides! This will help the top cover fit easier.
After you grind out the groove, it should look like this:
On the left side is the outer side of the box; the right image shows what it looks like on the inside. Note that both cuts are opposite from each other! This should make it a lot easier to install the top. Trust me on this.
I hope this articles will help whoever wants to do their own Heater Box rebuild. If you need help, just email me on the address above. Keep yourself warm during winter season. Happy Motoring.