Secondary Filter is the white one on top, and the Primary is the one on the bottom. I changed the Primary and Secondary fuel filters today on my 580CK diesel. I ran into a somewhat frustrating question regarding the WIX Primary fuel filter. It comes with a round cork doughnut-shaped gasket, about 3/8" thick. The directions say that on "some models" you need to first put the cork gasket in the bottom of the cannister, and then slide in the filter and then put it in place and screw/tighten the large screw on top. When I took the old one out, it was also a WIX filter with the same part number, but whoever put it in last did not use the cork gasket on the bottom. My first try with the cork gasket gave me the impression that it made things too tight since it seemed that the top of the cannister was not fully closing-up. I took it off and saw clear impressions where the bottom cork was pressed in a bit from contact with the metal, and the top had a circular impression where the housing had contacted the top of the filter. But I thought it was too tight, so I took out the cork gasket and tried the filter by itself. This time I made sure to have the side of the filter that had no impressions from the prior contact experiment face upwards so I could determine if the upper metal housing would leave an impression on the top of the filter. If it didnt, I would think that the filter was not making contact at the top, which would allow the dirty fuel to bypass the filter and go straight to the Secondary filter. So, I removed the filter again, and there was no impression on the top filter gasket, so I felt I needed to put the cork gasket back in. (I also noticed that the cannister did not completely close up along the top, so that apparently was normal). I plopped the cork gasket back into the cannister, put the filter in, and again mounted it to the housing. I admit that I had to crank down on that top 1" nut somewhat tight, but got her up and in place. I turned on the fuel and there are no leaks. Has anyone else ever had this same issue.......to use the cork spacer, or to toss it over your shoulder? Seems WIX should do their homework and give a list of models that need the cork, so we dont have to keep tinkering around, calling Bubba and Jethro for advice, and crossing our fingers when we throw the dart to decide what to do with it. To cork, or not to cork, That is the question. Here is the new and old Primary filters, and I failed to get a picture of the cork spacer:
The Case parts book shows that it is supposed to be installed. Part #4. http://partstore.casece.com/us/parts-search.html#epc::mr49912ar319866
Tinkerer......I looked at your link, and that shows a gasket going on the top "Secondary filter", not the lower Primary filter. The link shows 580 C models, so Im guessing that my older 580CK has a different set up. I tried searching on that site, but cant get anything to come up........I always find that Case parts site difficult to use....guess Im too much of a hillbillie to figger it out. See ya.
My older 188 diesel parts manual shows gasket #A 28056 (primary filter body to head) being used. How else would you expect it to seal?
Hey Old Magnet.......Yes, the Primary Filter has a large rubber ORing that fits in the upper cannister groove that fits to the head. I am referring to the extra cork gasket which is about the size of a silver dollar and about 3/8" thick, and the WIX directions merely say that some models require that it be used......that you slip it into the cannister before you slide in the filter. The WIX filter does have a thin sealing fiber on each end, so on models that do not need the cork gasket, it will seal. But if the cannister is a bit too long, then the filter will not be sealed at both ends when it is installed and screwed back up to the head. Confusing for sure.
If that is a big flat rubber washer on top of the filter in your second photo, then no you don't use a gasket on the bolt. The link I posted is for a 207 not a 188 like you have. This is a link to the 188 filters. http://partstore.casece.com/us/parts-search.html#epc::mr65627ar252625 Apparently you have the system in the bottom assembly in the illustration.
Tinkerer.....Yep, in Pic No. 2 from the top of this thread, that is the Secondary filter which is white and at the top. It does have a large rubber washer that seals at its top. If you look below this upper "Secondary" filter, you will see the Primary filter, which has a large 1" nut on its top that holds its cannister into place. This one also has a large rubber washer/ORing around its upper sealing point. This is the one that also came with the small cork gasket (size of a silver dollar or less), and it goes into the cannister before the WIX filter goes in. The Case parts diagram you sent does not show this cork spacer/washer. Im guessing that WIX decided to make just one filter to cover many applications, and their new filter is a bit shorter than the original.......and hence the need for the cork spacer. But it is confusing, and I bet alot of people are not putting the cork spacer in, and the filter is not sealing properly, and letting dirty fuel bypass the filter and go straight to the Secondary filter. Bummer.
Are you sure that cork 'O' ring you are referring to isn't #30 in the illustration ?? It is called a gasket in the part description. I doubt that Wix is selling an undersized filter for your application. To clear any doubt in your mind buy a set of Case OEM filters and compare the size of the Wix filter to the filter that the manufacturer is selling. In regards to that cork "O" ring there isn't supposed to be one in the canister. If there were it would be in the parts book. This is one more reason to buy OEM filters at least once in a while.
Tinkerer.......Nope, not #30 in the illustration. This cork one is larger, and the Wix instructions just say that "in some cases you need to add the cork spacer to the end of the filter". I agree with you....OEM filters would be the way to go, especially to have one and measure its length and compare that to the WIX filter length. Thanks for your input.
I opened another Wix filter and took this pic to show the cork gasket (spacer) that comes with it: