Firstly, searching BrickBoard and the Web it appears that Loctite is not to be applied to a brake hose female coupling to join it to a brake pipe male coupling. Nor is it to be applied to the coupling securing a brake pipe into a brake caliper. Is this correct? I had a mechanic apply green Loctite to my brake hose couplings & caliper pipe couplings! My thoughts are that the female & male brake couplings have a deep & fine pitch steel thread and are held to the body and strut to stop them being subject to vibration so Loctite is not needed? Similarly for the coupling securing the brake pipe into the brake caliper.

Secondly, my approach to release brake hose Loctited couplings (12 years & Loctite) was to apply a fine point propane torch to just one spot on the hose female coupling in the area where the pipe male coupling was inserted. Got this spot to almost red heat and then let cool down. Coupling separated but still needed a lot of force. One coupling would not separate so I filed a flat spot about 2 mm deep and 10 mm long on the female coupling deep enough to just where the thread of the male coupling became visible which shows up with a magnifying glass. This destroyed the structural integrity of the female coupling and allowed separation after some more heat & cool down. Might seem risky or tedious but took less than 10 minutes and did not damage male coupling on the pipe.

Thirdly, how do I release the brake pipe from the brake caliper. The caliper (Girling) looks like cast steel/iron so if I apply a propane torch to where the pipe enters the caliper could this crack the caliper? Plus its a huge lump of metal so I cant get a tiny bit of it red hot.