Oil Filter Leak

[Harry]

1966 230SL.  It seems that the bolt running up through the oil filter housing may be leaking where it tightens against the bottom of the filter housing.  So just curious, what are the correct gaskets/seals to use in that location (around the bolt and between the bolt and the housing)?  Also, I recall that the long bolt that tightens the housing to the bracket on the block seemed to not be good and straight the last time I installed it (which isn't optimum).  Can these long bolts be sourced or does someone have the specs to replace?

Thanks,
Harry

[Pawel66]

It is all there: https://www.sl113.org/wiki/Engine/Lubrication

And more if you search the Forum. If you type in search window e.g. "oil filter seal" (with parenthesis), you will get multiple hits on this topic.

[rwmastel]

With quotes.

[ja17]

Harry, besides the metal seal on the bolt, there is a small round rubber o-ring involved around the bolt also. It is on the inside of the canister under the sheet metal, hat shapped cover below the filter.

[rwmastel]

Yes,  parts 37, 39, 40 in the detailed diagram in the above link.  Make sure you have those.  Replace if not flexible like new rubber.

[Pawel66]

I did replacement of these bottom seals a couple of years ago. All parts were available at Mercedes (always try to buy rubber from Mercedes). The procedure is a bit tricky, it is described here on the Forum, e.g.: https://www.sl113.org/forums/index.php?topic=29618.msg214296#msg214296

One of the most important things to check, I think, is to make sure the upper cylindrical seal is fresh and soft and if not, that it is replaced. Sometimes it is forgotten as it may come off together with filter element and is not replaced. Then there is no oil filtration.

[Harry]

Thanks to everyone.  I need to get better with our search engine, no doubt.  I will absolutely have a look at the information out there on this subject.

Harry

[rwmastel]

Harry,  this might help.
https://www.sl113.org/forums/index.php?topic=30783.0

[Harry]

Just to be sure, I'm replacing the metal hat and all of the seals in the oil filter housing and the one in the oil filter mounting bracket.  For the filter housing, the order of the components in the housing:
- the larger rubber seal that seals against the filter
- then the O-ring seal that seals around the bolt (Looks like maybe this is actually installed into the underside of the hat
- then the metal hat
The metal hat contains the bolt seal and holds the larger seal in place - correct?  And in some of the manual photos, I see a large copper seal on top of the hat (facing the oil filter.  Is that correct?

Thanks,
Harry

[TJMart]

Just to be sure, I'm replacing the metal hat and all of the seals in the oil filter housing and the one in the oil filter mounting bracket.  For the filter housing, the order of the components in the housing:
- the larger rubber seal that seals against the filter
- then the O-ring seal that seals around the bolt (Looks like maybe this is actually installed into the underside of the hat
- then the metal hat
The metal hat contains the bolt seal and holds the larger seal in place - correct?  And in some of the manual photos, I see a large copper seal on top of the hat (facing the oil filter.  Is that correct?

Thanks,
Harry

Harry,

You are correct on all that you said except your last statement about "a large copper seal on top of the hat"

There is no large copper seal. There is only a small copper "crush washer" that you place on the long mounting bolt before you put it through the housing and then tighten the housing. Make sure you don't forget the large round rubber seal that goes on top of the housing in the groove. Don't overtighten the bolt but just enough so there are no leaks. If you overtighten you risk cracking the housing. 

Tony

[rwmastel]

Make sure you don't forget the large round rubber seal that goes on top of the housing in the groove. Don't overtighten the bolt but just enough so there are no leaks. If you overtighten you risk cracking the housing. 

And make sure you're not stacking a new housing groove seal on top of the old ones.  Two seals in this groove can crack the housing as well.

[Harry]

Thanks all.  One other thing - how is the old "hat" removed from the housing?  It seems to be pretty well affixed.  Do I need to heat it up (heat gun)?  It was installed underneath the lower, larger oil seal, i.e. I was able to remove that seal without removing the hat.

Harry

[rwmastel]

Harry, besides the metal seal on the bolt, there is a small round rubber o-ring involved around the bolt also. It is on the inside of the canister under the sheet metal, hat shapped cover below the filter.

Thanks all.  One other thing - how is the old "hat" removed from the housing?  It seems to be pretty well affixed.  Do I need to heat it up (heat gun)?  It was installed underneath the lower, larger oil seal, i.e. I was able to remove that seal without removing the hat.

What is this "hat" you guys are talking about?  Does it have a part number at the "230SL Oil Filter Seals and parts" diagram here?  Or, what part numbers does this hat touch?
https://www.sl113.org/wiki/Engine/Lubrication

EDIT:  I didn't read far enough down on that tech manual page!!  Now, seeing pics of a canister with a hat and without, I don't recall what my filter canister looked like.  (Car has been off the road for years.)  But, Harry, I don't think you should remove this hat.  I recall using a small 90° angle pick to get seals out of the bottom of the canister.

[DavidAPease]

Rodd,

If you scroll down the photos on the page you sent a link to, you'll see a piece described as a "hat shaped sheet metal cap".  According to the text with the picture, it doesn't seem to have a separate part number in the diagram.

Oops!  I see you already figured it out.

          -David

[Harry]

It is a unique part.  I bought two from Authentic Classics.

[Harry]

So are we confident that the “hat” sits on top of the lower rubber seal, rather than under that seal?  This is what is shown in the tech manual but I wonder.  If so, the hat has to be removable.

Harry

[dirkbalter]

May be that helps. I haven't done it but understand it's a pain to change. A little blurry but you can see the correct location of the hat.

[Harry]

Thanks Dirk.  Straight out of the BBB - which I have but didn’t check.  I was able to remove the hat but it was a booger to get free.  Apparently, these parts were replaced on this car at some point but installed in the wrong order.

Thanks again to all.

Harry

[Charles 230SL]

hello Harry, yes, the "hat" sits on top of the lower rubber seal and holds it in place - it (the hat) is indeed a booger to get out.
I finally just replaced it with the one Authentic Classics carries https://www.authenticclassics.com/seal-retainer-cap-Mercedes-Oil-Filter-Housing-p/auth-009843.htm

[kampala]

I replaced the seal under the hat a couple years ago and was able to do it without removing the metal hat.  Not easy but doable with picks by stretching over the hat bit by bit.  Took about 15 min. 

[rwmastel]

Dirk,
How are you attaching files as attachments instead of them being imbedded as images in the message?  They always show up inside the message for me (which I think is better, anyway).

I don't remember removing any mental part, but I guess that's an option.  Hopefully after remove & replace, the hat still seals properly and does not lead to drips out of the canister.