Know-How Notes: How to Remove a Rusted Bolt
There are many ways to remove a rusted bolt. For this guide, we focus on one in particular — Freeze-Off from CRC. Unlike other penetrating oils, Freeze-Off uses hyper-cold to shock the offending part, breaking the rust bond, and allowing the bolt to come out.
We had a 2009 Dodge Challenger in the shop that needed a plug removed from the exhaust. While the exhaust itself is made of stainless steel, the plug is steel. Whenever you have differentiating metals, corrosion and seized threads are a very real problem. This plug was locked tight.
- Because Freeze-Off has the ability to shock the rusted bolt, use a propane torch to heat the outside of the threads. This can loosen the plug. We got the part up to 186°C (366°F). Don’t touch it!
- Before turning the plug, apply more Freeze-Off. With the outside still hot, and the plug cold and shrinking, the bond should break fairly easy. Be careful, as this will create a lot of smoke.
- For additional leverage, use an Allen wrench and a cheater bar to break the plug free.
- Use anti-seize on high-heat threads whenever different metals are bolted together.
For more great tips on how to maintain your car and to find the parts you need, visit NAPA Canada.