Salut, I'm trying to say "Cover joints must be cleaned before replacing cover". However, I don't know the word for "cover"; I've tried looking up the word on wordreference and several forums but none apply to a protective cover that you'd find on machines and protect you from the moving parts.
To be clear, right now I have:
Il faut que nettoyer les joints de ... avant replacer (le/la) ...
My guess for the adjective, it'd be "les joints de protecteur" but I'm still at a loss for the noun. Any insight or guidance would be greatly appreciated!