In a message dated 9/29/16 18 22 40, rob@dumoulins.net writes:

No! Cut the old tubes out. New tubes from vendors are pre-cut into 2 pieces with rubber connectors. Might as well get new gaskets for the frame rail holes while you are at it. Getting those installed around the tubes and staying in the holes was the hardest part.

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Rob,

I suspect you have issued the right answer, to the wrong question. :>) Your answer seems to be addressing the radiator pipes, and it's right on. But he is asking about the HEATER pipes inside the cabin. They are secured with clamps that are spot-welded to the inside of the chassis. I have read others here describing how they replaced them, but I am fairly certain it's impossible to install new pipes with the engine in place. Removing the old ones can be done though, although it usually involves cutting them out in small pieces. Then you can run long lengths of heater hose in lieu of the metal pipes (sub-optimal solution). Mike In a message dated 9/29/16 18 22 40, rob@dumoulins.net writes: No! Cut the old tubes out. New tubes from vendors are pre-cut into 2 pieces with rubber connectors. Might as well get new gaskets for the frame rail holes while you are at it. Getting those installed around the tubes and staying in the holes was the hardest part.

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Rob, I suspect you have issued the right answer, to the wrong question. :>) Your answer seems to be addressing the radiator pipes, and it's right on. But he is asking about the HEATER pipes inside the cabin. They are secured with clamps that are spot-welded to the inside of the chassis. I have read others here describing how they replaced them, but I am fairly certain it's impossible to install new pipes with the engine in place. Removing the old ones can be done though, although it usually involves cutting them out in small pieces. Then you can run long lengths of heater hose in lieu of the metal pipes (sub-optimal solution). Mike