Oil filter housing query: "donut" seal...

[LFrank]

Yes, this old chestnut, once again, referencing the three rubber seals that do not come with the oil filter change kit.

The "garden hose" at top of filter is installed fine (top of housing); the little teeny one (installs b/t long bolt's washer and housing?); but the third, "donut" one has me worried.

I literally had to pry the old rock-hard one out from the bottom of my filter housing -- previously I had not known that it was even supposed to be changed.  But it seemed to fit under some sort of washer in the bottom of the housing? The new one I just dropped on the bottom of the housing, as there did not seem to be any way to secure it beneath any "holder", and plopped the new filter on top before securing.

Was that incorrect?

LFrank
Washington DC
65 230 sl - auto
DB334/Hellblau

[Naj ✝︎]

The inner lip of the donut shud go under the steel washer.

The new seal shud be soft and when oiled, it can be teased/slipped under without having to remove the steel washer. Becomes easier with practice [:p]

 

quote:the little teeny one (installs b/t long bolt's washer and housing?)

Actually fits in a groove in the filter bowl - can be a bit more challenging than the donut[!]

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naj

[Lilly]

I do not believe that you acted incorrectly.  My manual states to just make sure that it is centered at bottom of housing before installing filter on top of it and I face the "cupped" side of the "donut" upward to collect any sludge that may form.  I also, like you, fit the narrower metal washer on the outside of the housing b/t the bolt and housing but do not put the rubber o-ring there too because it would get squeezed to death.  I put the o-ring onto the bolt after the bolt has been inserted into the housing yet, I remain unsure as to what exactly the o-ring does or seals, it being narrower than the inner diameter of the filter cartridge.

Pagoda Lilly
'66 230 SL

[George Davis]

I replaced the donut seal recently myself, but my method differed from Naj's because I don't have his patience   .  The steel washer that holds the donut down is sort of top-hat shaped and fits on a boss in the bottom of the filter housing.  I used a thin screwdriver and hammer to lightly tap the steel washer out, with the screwdriver inserted through the bolt hole from the bottom of the filter housing, and tip of screwdriver under the inner lip of the steel washer.  Tapped gently so as not to distort the steel washer; came off easily.  With this washer and donut out, installed new donut and reinstalled the washer, tapping it back into place.

The o-ring goes inside the bolt hole in the filter housing.  There is a groove for it a few mm below the donut.  Getting the old o-ring out was a pain, you need something thin and pointed to stab it and pry it out.  If it's brittle it will come out in pieces.

The plain steel washer in the filter kit goes under the head of the long bolt.

George Davis
'69 280 SL Euro manual

[rwmastel]

Please read these threads.  The pictures and diagrams provided are very informative:
http://index.php?topic=3896
http://index.php?topic=2589
http://index.php?topic=1517
http://index.php?topic=999

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[LFrank]

Thanks for your comments, and the links. I figured I'd done it somwhat incorrectly -- but it's not leaking oil, and I at least correctly replaced the top seal; one out of three ain't bad?

And boy, does that one-piece screw on aftermarket filter look appealing!

LFrank
Washington DC
65 230 sl - auto
DB334/Hellblau

[rwmastel]

quote:Originally posted by LFrank

I figured I'd done it somwhat incorrectly -- but it's not leaking oil, ...

Frank,
Hi.  Just because it's not leaking doesn't mean it's all correct.  If that bottom oil seal is not sealing against the filter because the seal is upside down, it may be allowing the oil to bypass the filter.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420