I had a battle with my new heat riser spring. I was convinced I had it right like the picture in the manual, but after a call to JC they told me I had it in backwards. It was harder to install the other way, but works perfect like it should. I would post a pic, but my truck is in hibernation. The way it looks on mine, when the engine is cold the counterweight is upright, with the heat door open. Soon after starting it rotates down and closes off the heat from the exhaust manifold. If I remember, trying to figure it out the spring would wind-up tighter with a heat gun, and it can be installed backwards I found out.
Last edited by 4100 Fire Truck; Thu Nov 21 2019 10:22 PM.