Kind of stupid fuel filter question 85 300 SD
 

Really dumb, but crucial, question,

On the cannister fuel filter for an 85 300sd, what is used as a gasket? Is it an aluminum ring, a copper ring, a rubber gasket, or some combination of these? The shop guys were unable to help. Go figure.
Thanks
Jim

filter canister
 

The filter has a rubber ring built into it same as an oil filter...

The infamous 617 fuel filter setup is as follows:

Seal from the filter itself to the housing is the rubber ring on the filter.

The top fuel bolt that the filter spins on to has two seals. One seal is a little rubber ring that goes around the bolt itself. It may be hard and flat if it hasnt been change din a while. The other seal is a copper crush washer that goes between the bolt head and the filter housing.

It can be tricky to get it not too leak from the top fuel bolt. Tighten the top bolt to 20nm and hope for the best. There are threads hat talk about annealing the copper crush washer as well to attain a better seal.

dd

Thanks Dan
 

So Dan, is the rubber o-ring the same size as the copper crush seal, or does it fit inside of the copper ring? Above it? Below it?
Thanks a lot!
Jim

mine does not have the little rubber piece around the bolt, but it does have the crush washer. Mine does not leak, but it is put in rather tight.

Crush Washer
 

Is your crush washer aluminum or copper?

The #9 part is missing on my assembly. It is just a regular o-ring or a metal/rubber insert type covered by a copper crush washer?

Mines just a metal washer that is covered by a rubber o ring

Most newer bolts do not have that copper crush ring, if it's not leaking at top of bolt, you don't need one. My '82 240 needed one, I was unable to locate a copper one, used a composite instead, "#30 cap thread gasket stock no 35566B" that I got from my local hardware store, doing fine. The "o" ring, regular rubber #9, I think should be there. They are different sizes, the "o" ring fits in a groove machined into the bolt, the washer fits to just below bolt head.

Part#8:
http://catalog.worldpac.com/mercedesshop/sophio/quote.jsp?header=header.jsp&footer=&product=y3060-70385&partner=mercedesshop&baseurl=http://catalog.peachparts.com/&clientid=catalog.mercedesshop&cookieid=1U50RYHE224Z11G7IL


Part#9:
http://catalog.worldpac.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1U50RYHE224Z11IKCE&year=1985&make=MB&model=300-SD-002&category=E&part=Hollow+Bolt+Seal+Ring

Not sure if your 1985 uses the aluminum washer or not. My '82 does, but they eliminated it in a later year, but sure when that was.