74D Advanced Individual Training (AIT) Reconnaissance Practice Exam

The important thing to check is whether the O-ring has any physical damage that would prevent a proper seal. The seal’s integrity relies on the rubber remaining intact, so look for nicks, cuts, gouges, abrasions, deformation, or any cracking. These are signs the O-ring is compromised and could leak or fail under pressure. Color change can happen with aging or exposure but doesn’t reliably indicate a failing seal on its own, and dirt can be cleaned off without addressing the underlying integrity. If you see any damage or deformation, the O-ring should be replaced to maintain the system’s seal.