Many EU parts are labeled as to plastic type. However, this may be a small part that is not labeled. Basically, if acetone or ketone will melt the surface, it is bondable by various adhesives (J-B Weld, various epoxies etc.) If it is one of the slick "Polyethylene" plastics, virtually nothing will bond to it. It is a thermoplastic and some form of heat welding is the only manner of repair. For small cracks in non-polyethylene plastics, a drop of the horrendously dangerous methylene chloride/dichloromethane will almost instantly bond it. It is a very powerful solvent, thinner but considerably heavier than water. It is so dangerous that it is used to decaffeinate coffee beans! It "used to be" in all of the good paint strippers. So, beware! Just last evening, fixed a freeze-cracked polycarbonate Gardena garden hose manifold ("Hergestelt in Deutschland") with a drop or two. Repaired the tiny crack instantly and saved me $50.
Priced at $199/5 gallons, it is barely more expensive than gasoline.