Adrianmsmith donāt use that thread locker, itās permanent and if itās for the nut at the back, it will leak again within a few years if you regularly use the steam. This is because it sets hard, the constant expansion and contraction as the fitting heats and cools eventually breaks the seal.
I stopped ACS from using this product some years ago (probably 3+), and they now use Loxeal 18-10, which is easy to undo as itās not permanent, has PTFE, is WRAS approved and sets remaining slightly flexible.
https://tinyurl.com/2cjnyrmv
P.S. Unfortunately too many espresso machine manufacturers use Loctite 272 and similar permanent thread lockers, because itās cheap, sets quick and is easyā¦.hence fittings often leak and get damaged when people try and remove them
