1984 300D oll change anomalies... - PeachParts Mercedes-Benz Forum

colin4coolin · #1 08-01-2008, 10:37 PM

Hey guys !
I've had this diesel (he's called Otto) for 3 adventurous months, and i believe he's basically a good boy;Yesterday, I started with his first oil change.
Now this may seem trivial, but i did a site search, and did not find this situation as a topic.

Have new filter from Advance Auto Parts, but as for oil drain-plug gasket, it's special order ( ?! ). And other auto parts chains don't even have a listing for it ! ( Dealer item only ?! ) And everyone said that i should just reuse the original gasket !!! Mine has a copper washer gasket.
Finally, I found 1/4" I.D. copper washers, with correct O.D. at Ace Hardware, and painstakingly drilled them out ( PITA ) .
SO- I open up the new filter box, and see that they include a new large o-ring for the filter cover; wow, that's cool. Also a tiny package with 3 sizes of OIL DRAIN PLUG GASKETS !......D'oh !!! The smallest, no more than 12mm, fits the plug perfectly.
Things starting to fall into place, right ?..... NOT !!!
I open up the oil filter canister, check out the cover with its fancy steel tube protruding the full depth of the filter, and notice some "odd stuff".
There's a vent hole near the top. Maybe 1/16" dia. This had a little chunk of plastic debris protruding...Sorry, I should've photographed this stuff.

Well, I'm no idiot, so i remove it with needle-nose pliers.Then i spray some carb-cleaner into that port, and the larger one at the bottom of the tube.Am i mistaken in assuming that this needs to be an open connection between the upper side port and the tube bottom ???
Still, the tube seems to be completely blocked. I tried to run a fine steel wire (28Guage) through from the bottom, but it never goes more than 1.5 inch inward.
Somehow i fear that ignoring this situation would probably multiply the problem exponentially.
Finally, there are 2 small, thick O-rings near the bottom of this tube on the Oil Filter Housing. Caliper shows slightly different diameters. I pick at one, and it immediately disintegrates.Other one- likewise. The auto parts chains have no listing for such items. Again,"Dealer item only " !!!
WTF, as i shake my head, incredulously.
The only MB dealers in this region, have been proven to me, to be extraordinary rip-offs, for parts or labor ( at least on older models, such as Otto )
Well again i'm back to Ace Hardware. Good 'ol Joe helped me find O-rings in plumbing that fit pretty nicely, although only one size that sort-of fit both. It's called #78.
My questions are:
1.) Will the O-rings i found, do the job ???
2.) How to clear out that tube ???
3.) Why don't they include the 2 little O-rings with new filter ?!
Thanks for all your suggestions !
-Colin

vstech · #2 08-01-2008, 11:04 PM

the dealer will have this in stock for around $1, but they are just standard o-rings... that's why they harden and fall apart. IIRC, they are 6id/10od, and 7id/11od on the two orings. if your order them you will get two identical 6/10's the dealer will have them both... I think viton o-rings are available. but not worth it. the o-rings last several oil changes, but you should inspect and change them when they harden.
I don't remember if the tube is clear all the way through, or if the upper hole connects to the middle hole, and the lowest hole is blunt... sorry, not sure.

jt20 · #3 08-01-2008, 11:13 PM

there is a check valve in that shaft. Oil does pass through it

tangofox007 · #4 08-02-2008, 02:21 AM

Quote:

Originally Posted by colin4coolin;19279532.)[B

How to clear out that tube ???[/B]

Don't. There is a check valve in the lower section which prevents oil from flowing up the tube. You are trying to fix something that isn't broke.

Quote:

Originally Posted by colin4coolin;19279532.)[B

[/B]
Why don't they include the 2 little O-rings with new filter ?!

The o-rings last a lot longer than a filter. They don't need to be replaced at every oil change.

t walgamuth · #5 08-02-2008, 06:53 AM

I have driven well over a million miles in benzes, mostly diesels and have never yet changed the o rings on the shaft.

I Imagine I probably should have but I am not sure of the effect of not doing so. I have never had one disentegrate on me.

Tom W

colin4coolin · #6 08-02-2008, 07:22 AM

Thanks guys !
I measured that #78 O-ring from Ace, and it looks like the right size.
And Otto's smiling now.

tangofox007 · #7 08-02-2008, 11:01 AM

Quote:

Originally Posted by t walgamuth

I have driven well over a million miles in benzes, mostly diesels and have never yet changed the o rings on the shaft.

I Imagine I probably should have but I am not sure of the effect of not doing so.

Tom W

A poor seal will allow oil in the filter housing to return to the crankcase unfiltered.

t walgamuth · #8 08-02-2008, 12:14 PM

Well, that would also allow the filter cannister to empty, right? That would contribute to bearing starvation on startup.

I'll have to get some new seals.

Tom W

Diesel911 · #9 08-02-2008, 12:28 PM

Hard to see on this pic but 20 and 21 are the O-rings on the end of the shaft and the check valve is up a littli higher.

dieselnutnj · #10 08-02-2008, 01:27 PM

I use the purolator filter Advanced sells. I'll get you the number when I get home. Those little O rings are avail easily in any assortment they sell. Nothing special, but they are very important indeed. The purolator filter comes with all the rings including one for the oil cooler should you venture to draining that. Even a nice baggy to put your really messy old filter in! That is the cheapest filter at about 7.00 I have ever bought for mine. You want a messy one to change.. try an old 115 chassis 220 or 240 D.. comes out from the bottom.. and yes. .the bolt goes up through the housing!!!! messy.

t walgamuth · #11 08-02-2008, 04:58 PM

Thanks very much.

Tom W

t walgamuth · #12 08-02-2008, 04:59 PM

Quote:

Originally Posted by dieselnutnj

I use the purolator filter Advanced sells. I'll get you the number when I get home. Those little O rings are avail easily in any assortment they sell. Nothing special, but they are very important indeed. The purolator filter comes with all the rings including one for the oil cooler should you venture to draining that. Even a nice baggy to put your really messy old filter in! That is the cheapest filter at about 7.00 I have ever bought for mine. You want a messy one to change.. try an old 115 chassis 220 or 240 D.. comes out from the bottom.. and yes. .the bolt goes up through the housing!!!! messy.

Nothing beats a 616 617 for changing the filter. I have done it in pretty nice clothes without any disasters many times.

Tom W