The Stovebolt Site Forums The Shop Area Engine Shop 235 thermostat question

Here are a couple of views of a "jiggle pin" in an old but still good 160 degree thermostat. Hopefully a trapped air bubble is part of your problem. Also, granulated citric acid can be purchased on Amazon. I get it to use as toilet bowl cleaners as it will dissolve minerals. I'd need to look but as I recall 6 tablespoons in a 32 oz spray bottle will give you about a 6% strength mixture. You'd need more than that to dissolve heavy rust. As I said, I've used CLR full strength and a another fellow last night told me he had used a product called "Evapo-Rust" but said it works more slowly so you have to be patient.