Hi all. Just thought I would put up the difference between a genuine fuel filter and an aftermarket one. The thing that I noticed when I bought the new genuine filter from Nissan is that it comes with two rubber o rings now. In the past when I have bought them they have only ever had the one that goes on the bottom of the filter where the water drain and sender screws in. This is how the new filter comes. The o rings look like an after thought or an update to how I use to buy them.
This is the difference in size from the genuine and a Nippon max brand filter. The Nissan filter on the left is bigger. This is how I found and have always recalled the under side of the primer housing being. No o ring. I didn't remove it if it ever was there. This is how it should look with the o ring in place. This is where the second o ring goes. Complete and back together. Ready to go back in. I have found that using the aftermarket filters has given me some running problems from time to time. The last issue I had was a massive flat spot on gear changes. I can only assume that the filter was letting in air from the missing o ring. I don't know if Nissan have just started adding this o ring as I have used genuine filters in the past and have never been supplied the small o ring that goes on the primer I have only ever been supplied the bigger one that goes on the water drain and sender assembly. I hope this helps people that didn't know about this. Cheers Brad.