This page covers the main heater tube replacement. I decided to replace this tube because the old tube had rusted out and was replaced with a thin metal tube by the previous owner. It did not allow much heat all to make it up to the front of the bus.

I used PVC pipe and a Bilge Blower to help get the heat from the engine to the front of the bus.

Front part of main pipe. Rusted, but usable.

Rear part of main pipe. Pretty bad shape.

This is what I started with once I removed the old tube. The front end of the tube was rusted, but still had some of the tube at the end that I was able to attach the PVC pipe to. The back end of the tube was rusted away and would need some kind of adapter to go from the oval rusted end that it had now to the round PVC pipe.

I decided to use PVC because I had seen several other sites where people had used it. I heard that gas could be produced from the pipe getting to hot, but nobody that I talked to had this problem yet.

I used a piece of stove pipe to go into the rear part of the main tube. It had to be crushed down to fit the oval, but it seems to work ok. I probably lose a small amount of air around it because it is not sealed at all, but I think the majority of the heat will pass into the PVC pipe.

The next part was a 12 inch piece of 2 inch PVC pipe. I used a rubber 2 inch to 2 inch connector (from Lowes) to attach it to the metal tube. The metal tube was a little large, so it ended up on the outside of the rubber.

I then connected the 2 inch pipe to the 3 inch end of the Bilge Blower. I used a rubber 2 inch to 3 inch adapter to make the transition. The Bilge Blower came from Marine West Supply Company. It cost about $30.

I adjusted the cable that connected to the front tube and allowed heat to enter the rear of the bus. It just needed a little PB Blaster to get it real loose and the cable needed to be adjusted a little. No it closes completely when the lever is moved on the dash. Even though I fixed this, I still decided to cap off the tube that would take the heat to the rear of the bus. The paper tube that was used for this was in bad shape and I have a rug that goes over the vent holes in the rear anyway. So why waste the heat. This was accomplished with two 2 inch rubber caps. One on the heater tube and the other on the tube as it enters the bus. Do not want any small critters going up this tube and into the bus.

I then attached the other side of the blower to a 3 inch piece of PVC pipe with a 3 inch to 3 inch rubber connector. This piece of pipe was about 24 inches long. I attached this to the original tube in the front of the bus with another 3 inch to 3 inch connector. It was a tight fit and with the ridge in the metal pipe, it was not ideal but it is very tight. This piece could use some POR 15 in the spring.

Next I had to get some power to the Bilge Blower. I decided that the easiest way was to jump off the relay that was in the rear of the bus. This relay controls the auxiliary fan that is used to push heat from the rear of the bus through the heat exchangers when the heat lever is on max. I spliced into the hot wire and routed a red 12 gauge wire from this point to all the way up to the Bilge Blower. I need to come back and reroute this wire since it looks bad the way it is. I was getting impatient and wanted to see results. I then ran a ground wire over to a hole in the frame and secured it with a bolt and star washer.

Now for the test, when I turn on the bus and fire up the heater, I hear this load humming coming from heater and air flows out of the vents nicely. It is a little loud, but I guess it will have to do for now. This combined with the fan on the engine really does a nice job of pushing the heat to the front. The first test blew a bunch of trash out of the defrost and all over the dash. Looks like a mouse had a home there at one time. Not any more. I got under the dash and removed all the plastic pipe and cleaned it all out. Hopefully the mouse was not further down in the tube.

I have not used this in the cold yet, but I think it will do ok for

now. I have intentions of adding a gas heater to the bus, so this mod may become obsolete eventually. Since I have the Webber progressive carb, I cannot drive the bus in really cold weather anyway. That will be fixed another day......