It's still on the plane. If nobody tested it at the pressure a plane is at, and it turns out it explodes and injures the crew, that's not great.
Fun fact, if parts are around 30k they can be treated as not worthy of repair. Instead, discard them and nuy a new one.
https://en.wikipedia.org/wiki/Galvanic_corrosion
Mercury versus aluminum: https://www.youtube.com/watch?v=IrdYueB9pY4
In an earlier life, I shipped items requiring this particular hazmat label on packaging: https://www.safetyemporium.com/12332