HELP! Problem changing fuel filter

[kdr3885]

I'm changing the fuel filters on my 06 F350 PSD. Bought fd-4616 at dealership. Pulled old primary filter. It looks different . New filter has o-ring on end bayonet fitting. End fitting is longer. Old filter has no o-ring. On the oreily website, it lists to part #s fd 4604 and fd 4616 for my make and model year.

Need advice, please.

[HAM_RADIO_MAN]

Thats the problem with non OEM filters they sorta fit and they sorta filter. Could your old filter be non-oem.

[Lilpooh]

Your OK, the 4604 was old stock motorcraft, they updated to a new design 4616.

You can see it hear.
http://www.dieselfiltersonline.com/F...4-Fd-4616.aspx

[sinner6.0L]

the o-ring seals out water and dirt making sure all fuel passes through the primary filter first. in theory it should keep the smaller finer filtering secondary filter cleaner

it also means a restricted filter isn't going to bypass any fuel so it's even more important you service your filters regularly