Return fuel line clip

[pleasestartnow]

Hi folks, i have a 2014 1.6tdi 102bhp version. Just had injector 3 replaced and after two days of driving with no issues i got home yesterday and noticed diesel leaking from the van. I could see the low pressure line from injector 4 was loose so i pushed it back in, heard the click and went for a short spin. No leak, this morning i went for a short spin and when i was nearly home i could smell diesel so i pulled in and checked and say that the line from injector 4 was loose again. I tie wrapped it in for now just as a temp fix.

So my question is, do i need to take out the metal clip before i push back in the fuel line or is it ok that it pops in with the audible click? Also, the metal clip on that line seems looser than the other injector clips so im wondering if i just get a new one will that solve my problem and if so does anyone know the part number?