This hardware is made up of non-ferrous metals. Maintenance of capacitors is the next issue. The ceramic body should not be cracked. The interior metal plates should be shiny as you view them through the glass. As with coils, check all hardware should be checked for tightness.
Loose hardware makes for a poor electrical connection.
Heat will build up at the loose connection and eventually will eventually cause failure or component damage. Don't over-tighten the hardware but make sure it is snug. Over-tightening vacuum capacitor brackets can cost a fortune. Handle these components carefully. For best results, use the factory-supplied mounting brackets or clips.