Description: Brake Booster Firewall Gasket
Model: Mustang, Shelby, Cougar
Model Options: All models with disc brake option (excluding BOSS 429)
Service #: C9ZZ-2B022-A
Accuracy Rating: 9
Best Repro Available: YES
Most don't know about this gasket that was used to seal the space between the firewall and brake booster mounting flange because there is usually nothing left of it when you take off the brake booster. It helps to keep air and water from entering the passenger cabin so its worth installing even though you hardly it see the edges of it when installed.
Two types of material are available: a lighter open-cell foam thats considered the most common, or (this one) a more dense, modern open-cell foam that's much more durable. The picture below of an original looks like its a dense closed foam version.
This part is proudly made right here in the USA by die-cutting 1/8" thick polyurethane foam rubber that meets Ford's original ESA-M4D57-A specification.