Will Fix-a-Flat Fix a Valve Stem Leak

Can Fix-a-Flat Seal a Leaking Valve Stem? No, Fix-a-Flat will not effectively fix a valve stem leak. Fix-a-Flat is designed to seal small punctures in the tread area of a tire, but it won’t properly seal leaks around the valve stem, especially if the leak is due to a cracked, loose, or damaged valve stem….