I have what DC and Towcat are talking about on mine and in the shop! I love the stuff, easy to work with and no rust (in the shop). We used it at the machine shop to route air from two outside compressors throughout the shop, it has been there for years with no problems, but I would isolate it from vibration as Towcat said. We just put a piece of rubber line between the entry point and our compressors to handle it, made a loop, like a drip loop and hooked it together. My compressor on my truck is electric, so I didn't have to go to the engine, but I would definetely get a good 3 foot tool lead and use it from an engine mounted compressor to the chassis mounted line.