Fuel filter seals

[Mike K.]

I've replaced the fuel filter on my 2001 Duramax several times before without a problem, but somehow I'm having trouble with the center rubber seal...

I removed the old filter, and the black rubber center seal (shown to the right of the filter in the pic) came off with it, along with the larger O-ring. I put a new O-ring on the new filter, and moved the center seal from the old filter to the new one, but I can't get the new filter to go on... I can only get it to start threading if I remove that center seal.

That center seal came off with the old filter, so it needs to go back on, right? It does feel like there is some sort of rubber seal in the center of the filter mount. The second pic shows the filter mount, where there does appear to be some kind of rubber seal in the middle. Can anyone confirm what I'm seeing?

I have no idea how something that came off with the old filter wouldn't fit when I try to put the new one on?!

Pics:
http://odo.colorado.edu/~kionka/fuel_filter.JPG
http://odo.colorado.edu/~kionka/fuel_filter2.JPG

[DmaxMaverick]

Welcome to the Forums!

You have to install the center seal on the filter, then install the filter. If you put it on the nipple, then try to install the filter, the nipple will prevent the seal from entering the filter because it is expanded. Everything you have in the pics looks right, and should work if you install correctly. Take that center seal off the filter housing, install it on the filter and it should go right on. It is also easier to get the large O-ring to stay in place if you fill the groove in the filter with grease or heavy lube before you press in the O-ring.

[Mike K.]

Thanks for the reply... It turns out, the new filter must have come with another center seal, as the nipple still had one on there. Once I removed it, the new one went on fine with the center seal installed on the filter. I swear the old filter came off with the seal on it, but I must have got mixed up somewhere.

I primed it as instructed by the manual, but the truck still didn't start initially. It took a couple tries of re-priming but it finally did start... I've replaced the fuel filter at least 4 times before, but never had this much trouble getting it to start afterward.