Hi guys,

Ever since I got my 240D 3 years ago, I always have trouble with fuel leaking from where the banjo bolt connects to the housing. When I first got the car, it had nothing sealing it, and when I swapped in a new fuel filter, it of course leaked like crazy. I ended up using a metric O-ring, and it works OK, but the O-Ring tends to get crushed and squashed and leaks after a couple of hundred miles.

I then went and purchased metric copper crush washers, but it seems to take an awful lot of force with the 22mm wrench to get it to seal. I'm thinking that MB must be using something else.

What SHOULD I use? What did the factory use? What is recommended?

Thanks so much.

Packman

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83 240D - 4 speed manual - Manilla Beige
189K miles, Tachometer mod, cool wooden shift knob from PeachParts, CocoMats, Original factory paint, manual windows, manual sunroof. Starting to add AudioWrap to this car too!

the seal is more about the orings inside on the bolt itself. have you replaced those?

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Current fleet
2006 E320 CDI
1992 300D - 5speed manual swapped

former members
1984 300D "Blues Mobile"

1978 300CD "El Toro"

Yes, I have replaced those. Are you saying that I don't need anything on the top if the O-ring inside is properly sized?

Thanks,

Packman

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83 240D - 4 speed manual - Manilla Beige
189K miles, Tachometer mod, cool wooden shift knob from PeachParts, CocoMats, Original factory paint, manual windows, manual sunroof. Starting to add AudioWrap to this car too!

There are two "styles" of filter head and banjo bolt.

The "Early" version uses one o-ring and a copper crush washer.

The "Later" version uses two o-rings, no crush washer.

Here is a picture I took of my "Later" style banjo bolt on my '85 300D. Notice that it has two obvious spots for o-rings.



If this is the style on your car and it's not sealing well you're simply using the wrong size o-rings.

You can try buying them directly from Mercedes or from Pelican Parts using the part numbers, that will get you the exact o-ring that Mercedes intended to be used in this spot.

I can't find a good picture of the early style online. I'll have to take a pic from my '79 next time I do the filter...

However it only has a spot for one o-ring, the lower one. The top of the bolt it sealed with the crush washer. Indeed you do have to tighten it pretty tight to get it to seal, since you have to crush said washer to get a good seal. Once crushed though it seals fine.

If you have the early style after all and find it to be frustrating to get a good seal you can always swap in the late style filter head off a junkyard car.

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1979 300D 040 Black on Black - 1985 300D Maaco job (sadly sprayed over 199 Black Pearl Metallic) on Palamino

http://i.imgur.com/LslW733.jpg

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i do believe that would solve your problem there. The crush washer may be keeping it from sealing properly by not allowing the bolt with the orings to seat down far enough inside the tapered hole in the filter housing.

Also, Look for nicks in the metal around the top of the housing at the bolt hole. could be something bad enough to not let it make a proper seal.

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Current fleet
2006 E320 CDI
1992 300D - 5speed manual swapped

former members
1984 300D "Blues Mobile"

1978 300CD "El Toro"

Over tightening the bolt
With crush washer will cause it to leak

Aluminum. I could never get a copper seal to work, either. Aluminum works for me every time. (This assumes that you have the single o-ring type bolt.)

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When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

Looking on the top of your fuel filter housing is a MB part # starting out with 615-xxx-01-xx and this one uses the one "O" Ring and Crush Washer.

The later up dated filter housing has a Part# of 615-xxx-02-xx and uses the 2 "O" Rings and NO Crush Washer.
If you have this one and are using a Crush Washer, this might be why you have a leak, the "O" Rings are not seated because the CW has raised them a bit from their seats.

It might be 1983 this was changed.

X 2 on using an aluminum washer, it would be softer than the copper to make a good seal.

Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

Yeah, check the number on your fuel filter head, the "01" uses the crush washer as mentioned, copper has always worked for me, but there you go.

First pic is of the "01" banjo bolt, second has the composite washer size.

I've also used a composite washer I picked up at the local hardware store, works fine.

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83 SD

84 CD

Thanks guys, this is very helpful. I have a banjo bolt that doesn't look like either of the ones shown in this thread. It looks like the one in post #9, but it doesn't have the little tube that extends down into the filter. It's just the larger diameter portion.

At any rate, I have temporarily sealed it with an o-ring, and I will likely use the composite washer idea for now, until I can get to a picknpull and get a later model assembly. I did check the sealing surface of the current housing, and it's rather pitted, likely from age and use. Short of sanding it flat, which will likely remove a fair amount of material, I think that a composite washer is the best idea.

The copper washer seems to suffer from the "it's not flat enough to seal" and "if you torque it down too much, it's just going to leak." syndromes. Therefore, either a replacement housing in better shape or one of the later design or using a different, more pliable sealing material is in order.

Thanks again,

Packman

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83 240D - 4 speed manual - Manilla Beige
189K miles, Tachometer mod, cool wooden shift knob from PeachParts, CocoMats, Original factory paint, manual windows, manual sunroof. Starting to add AudioWrap to this car too!

Big thank you for this post, toomany MBZ!

The composite washer worked like a champ. I was able to get one at the local Ace hardware - it was easy to find in the plumbing section, as you photographed the package! I was able to match the bar code number exactly.

What's great about this solution is that the composite washer takes a LOT less pressure to seal properly, so I no longer have any issues with torquing the fuel filter. It has always bothered me that it takes so much pressure to deform the crush washer in order to get it to seal, and using this new method allows the whole thing to be leak-free and under a lot less pressure, which I think is a good thing.

Thanks again guys, you guys are the best.

(Charlie - I will still likely comb the picknpull to get a later model system with two o-rings, but I'm no longer in a hurry for one... thanks!)

Packman

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83 240D - 4 speed manual - Manilla Beige
189K miles, Tachometer mod, cool wooden shift knob from PeachParts, CocoMats, Original factory paint, manual windows, manual sunroof. Starting to add AudioWrap to this car too!

Just wanted to say thanks to everyone contributing to this thread, and to the OP for starting it. I'll be hitting the local Ace on the way home from work for this exact solution.

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617 swapped Toyota Pickup, 22-24 MPG, 50k miles on swap

This forum is about folks helping others.

Glad I could contribute.

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83 SD

84 CD

You better hurry, they are crushing them at an alarming rate.

You will find the filter housing with the 02# in the SD as well as the 300D, as I said above, think 83 - 85.


Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

FWIW ,

My 1984 300CD has the earlier single O-Ring and aluminum crush washer typ and yes , it weeps .

To - day I was in a Pick-A-Part Junk yard that had several 300SD's , the 1983 and 1984 both had the upgraded filter head and double O-Ring bolt so I bought both and am off to try to find the correct Mercedes O-Ring part # as this weeping drives me nuts and the Diesel Fuel attacks and destroys every thing rubber and plastic it touches like my new motor mounts , sway bar bushings , ball joints (the boots) , shock bushings , on and on....

THANK YOU for this thread ! .

Only one lonely W-123 Sedan in the biggest Junk Yard in Sun Valley , my how times have changed .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better