Cafiza is the industry standard when it comes to removing oily coffee residue. Soak your parts in it to remove built-up grime, or use it for a daily backflush. (Backflushing is when you force water ...
Though difficult to mod, repair ... the boiler and gaskets. Below, you’ll find a list of products and parts that I used — or wish I’d used — while restoring my Gaggia Classic.