[mr rooney]

Just changed the fuel filter on my tdi 130 sport but managed to loose the new blue o ring seal so i have re used the old black o ring as the old blue o ring broke on removal. Car started instantly with no fuel leaks. If any problem occurs i will have to purchace some new o rings or at worst buy another filter.
Just wondering why the o rings are blue and black?

 

[chittychittybangbang]

As far as I can tell, they are the same size. It's possible one is softer. If you have a no leaks, no problem!