My last oil change 300SD, I did not have any tiny O-rings
 

When I was doing this job last I remember pulling out a long rod like thing and seeing atleast one o-ring on this rod. There may have been two, not sure. Anyway my filter kit had no such tiny o-rings so I just reassembled it but I want to get these for my next oil change. I did not even touch them but they looked worn.

I read about these getting brittle and need changing. My oil pressure is fine on idle. In center of range when hot then pins when I take off.

My question is:

1. How many are there on this rod. One or two?
2. What are they for.
3. I can't find them at Phils, anybody can find them for me? I'd appreciate it.

I see others get them at hardware store but I'm not sure what size or material to get. Anybody's help would be appreciated.

Just do it next filter change.

Yes I plan on replacing next time. Thanks for reply bgast.

They did not come in my filter kit.

I looked at Phils parts and I don't see them listed there.

Get one of these kits for your next change: http://catalog.peachparts.com/ShopByVehicle.epc?q=&yearid=1982%40%401982&makeid=63%40%40MERCEDES%2DBENZ%40%4063&modelid=6206%3AMBC %7C1510%3AED%7C10000134%40%40300SD&keyword=filter&subcatid=P:240348@@Oil+Filter+Kit&mode=PA

The size of the 2 O-rings is 6x10x2mm. Internet part sellers have them and sompleace like the local NAPA may have them.

Yeah, they'll be OK, and any auto parts store should have 'em.

Thanks guys for the replies. I'll check into Kit and NAPA.

That link is dead. I'll ask Phil when I order when I get my list made up. That pulls up cooling system parts but thanks anyway. I wrote down the size that will help me. Not really sure what they do but they are there for a reason I'm sure. Thanks

I have tried two of these links this AM for Phil's parts and both were dead. Maybe it is a problem with Phil?

Are you sure they are both the same? I replaced mine in my OM602 some time ago, seem to recall there were two sizes. Maybe different for different engines....

nope, they are NOT the same size. you can use same size, but one will be stretched out.
the larger one is 7/11mm

I do not know about the OM602 but when you go to *************** and run my 84 300D trhough their parts search they show that the car needs 2 of the 6x10x2mm O-rings for my vehicle. They show no other size. And the 1 size works.
Also the other part places I have checked show only 1 part number for the O-rings that go on the bottom of the Oil Filter rod/stem.
At the Russian EPC site the show item #182 Seal Ring part 0159979448 as 2 each and no other size listed.
http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=123130&M=617%2E912&GA=722%2E118405&GM=716%2E005++++++++++++++717%2E400&CT=M&cat=1 43&SID=18&SGR=045&SGN=02

Perhaps someone who can access the Mercedes EPC site will verify this.

However, one of our Members on his own has gone to the trouble to find a larger O-ring for the upper one. Maybe he will read this thread an pass on the size he used. He has a post somewhere on this.

I got mine from dieselgiant's site. Im pretty sure my engine ate them because I did my first oil change after I bought the 240d and they were nowhere to be found.. :o

*EDIT* The forum keeps eating the link, I sent it to you in a PM

BTW, as to the function... If I recall correctly (and I may not because I don't have as many brain cells as I once did), when I changed mine I concluded that the o-rings separate the oil flow to the two parts of the filter. The diesel filters have a full-flow section and a bypass section. All the oil going to the bearings passes through the full-flow section unless the filter is plugged or the oil is too cold to pass through it, in which case a bypass valve - no relation to the bypass filter - will allow unfiltered oil to the bearings, as unfiltered oil is better than no oil. The bypass filter is a much finer pore size and gets a smaller amount of oil flow that I think is simply returned to the sump. The idea of the bypass filter is that it keeps cleaning up the oil in the sump, mainly for soot control. The full-flow section protects the bearings from the big chunks. If the o-rings are worn or missing, the oil flows will mix and the filter will not do its job properly. I don't think it is catastrophic, but it isn't good.

You can get them through Fastlane. Try this link - http://catalog.peachparts.com/item.wws?sku=W0133-1644350&itempk=77321&mfr=REI&weight=0.02