W123 Fuel Filter (01 Style)---DIY Options 4 Bolt Leak (No Success Yet) - PeachParts Mercedes-Benz Forum

iladelf · #1 08-29-2016, 10:29 PM

So this past weekend, my great niece (all of 9) helped me to do a diesel purge on my 81/84 "hybrid" 300D. Used SeaFoam (it worked, IMO...the glass bottle I used was almost BLACK with fluid when completed) and once completed, decided to replace the filters. Jeebus Peebus...apparently that was the hard part!

Naturally, I have the "O1" secondary filter housing (swell), so I decided to use the aluminum crush washer again, and replaced the lone O-ring with one from a metric HF set that appeared a match. Upon tightening everything up...ooozy McFloozy out of the top of the bolt, and cranking it down didn't help, either (btw, a 7/8" socket or wrench will work on that bolt---mine must be 22mm in size). Meh. Tired and losing daylight, I decided to fiddle with it later.

Today, I tried using a combo of the following, a 3/4" fiber washer with a 3/4" machine bushing (see items below). Umm, no.

http://www.menards.com/main/tools-hardware/fasteners-fastener-accessories/washers-spacers/flat-washers/3-4-x-1-fibre-washers-1-pcs-box/p-1444440193352-c-8945.htm?tid=1095281669387988619

http://www.menards.com/main/tools-hardware/fasteners-fastener-accessories/specialty-fasteners/bushings/3-4-x-1-1-4-x-14-gauge-machine-bushing-1-pcs/p-1444440112760-c-9547.htm?tid=7655826416167690244

Basically, I put the metal washer on next to the bolt, with the fiber washer underneath that. I noticed they both "wallered around" the bolt, so I wasn't sure they'd seal. Yeah, when I tightened and started...leaked like a sieve. Next attempt? Straight fiber washer. Tightened the beejeebus out of that, sprayed Brakleen, let dry and started. It seemed as though it was not going to leak, but occasionally, I came up with fuel on my fingers when touching the area around the washer. And it seemed to be weeping, so...attempt 3; bolt/fiber washer/old aluminum crush washer/housing (in that order). Thought perhaps the combo would keep it from leaking and...success? Perhaps; didn't seem to leak, but I decided to drive it and see. 15 minutes later and...weepy, weepity, weep...similar to when you found out what happened to Ol' Yeller. Again, tired and losing daylight...decided to give up and try again later.

What I'm looking for is a solution I can suggest that nearly ANYONE who frequents this forum can find easily in their area. With parts becoming more and more difficult to find, this is going to be an ongoing concern with these filters. What I will try next is the following:

1. The Right Stuff, from Permatex (see link below). Look, let's face it, all we really need is a good seal between the housing and the top of that wascally bolt. This stuff is designed to form on surfaces and conform to any imperfections on said surface (which I think may be our problem in the first place...because the housing has gotten gouged over time which creates a leaking area), and can be tightened and used immediately. Only issue (besides it's expensive)? Says it's not supposed to be used where it will come in contact with gasoline. Well, diesel ain't gasoline, so...I think it's worth a shot. I'd use it by putting a bead on the housing, then immediately putting the bolt/filter on and tightening.

Permatex 3 oz. the Right Stuff 1 minute gasket 25229- Read2Reviews onPermatex #25229

2. Peel & Seal. I used this on the roof of my house to seal a leak around a bathroom vent pipe. It's basically a thin aluminum with a rubber backing and adhesive; in this case, I'd cut a piece to fit the housing, cut out a hole in the center, then install the bolt/filter and tighten.

Shop Peel & Seal Instant Waterproof Repairs 6-in x 25-ft Aluminum Roll Flashing at Lowes.com

3. O-ring on top of the bolt itself that fits tightly (bolt/o-ring/housing). If I can find one that's a match, this might be the easiest fix of all. After all, an o-ring smashed down should likely seal the leak, as I think it would be self-conforming to any imperfections in the bolting surface on the housing.

Stay tuned. Will likely try these fixes tomorrow or the next day.

disqo · #2 08-30-2016, 01:30 AM

I seem to recall there being two o-rings on that big bolt.

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optimusprime · #3 08-30-2016, 06:55 AM

I would get the right crush washers .If they move about like you say, then its the wrong part.On petrol pumps the crush washer is copper or brass . And its important that you use the right one I pick a few up before i start the job . Never had one leak out yet.Maybe it was not replaced the last time .So now its a second time fit , leaks . Some washers are alloy washers with rubber centre .But as i have petrol , i have never seen them on petrol system

charmalu · #4 08-30-2016, 12:01 PM

Here is a good thread explaining the fuel leakage problems.

Fuel filter O-ring

and another

How to seal a W123 Fuel Filter Banjo Bolt?

There is a part# on top of the filter housing.

615-092-01-08. you will have one rubber "O" ring on the center bolt and use one aluminum crush washer under the head of the bolt.

615-092-02-08 you have two rubber "O" rings on the center bolt, and NO crush washer under the bolt head.

The aluminum washer is a one time use for the most part. trying to reuse one will usually result in a leak.
One problem from what I have seen on the 01 version, is people keep cranking down on the bolt to stop a leak,
and after many years of this gouges into the metal surface and it is no longer flat to give a good seal.

iladelf · #5 08-30-2016, 01:21 PM

Yeah charmalu, I've read that (and several other) threads. The #30 composite gasket toomany mentions in that post...well, the closest thing I could find in my area off the shelf was that fiber gasket I mentioned. It's raining here today, so venturing outdoors to fix won't happen. My garage has very little room for me to work; just enough for me to get my car in it (and poor lighting as well).

I still think one of the 3 ideas will work; if not, and I have to order a kit from someone, I may level off the housing's mating surface if necessary, due to the potential gouging you mention. My father (the previous owner) was always torquing things down to 1 million ft lbs. I swear, he did that in virtually every car he ever owned!

Again, the reason why I'm trying to do this with commonly available items is so there can be a "fix" that any of us with the "01" design can use if needed, without having to order a kit online.

charmalu · #6 08-30-2016, 03:49 PM

Here in the parts catalog is a section of Miscellaneous & Hardware here are the washers.

1980 Mercedes-Benz 240D Base Sedan - Miscellaneous & Hardware - Page 2

Order the aluminum one`s.

iladelf · #7 08-31-2016, 12:39 PM

First off, didn't realize the Pelican had these particular crush washers (thanks charmalu), so it's good we can order them still from our forum's sponsor. That said, my use of The Right Stuff has worked...so far. It's not cheap (even the smaller bottles are $14 and up), but can indeed be placed on the housing, tightened immediately and the vehicle is ready for use. Is it messy? Yep; kind of hard to lay an accurate bead and then move it around if needed, because it sticks to everything (make sure your mounting surface and bolt is clean and dry before using), but again, seems to be working. I drove the car around for about 5 miles yesterday after completing the repair, and it appeared to hold. After a nearly 50 mile drive today, was completely dry. It does look more "skinned over" or hardened today than yesterday.

The question is, will it hold up long term or break down eventually? That's something I'll have to report back on later. The good news is this; should you need to swap your secondary filter out in an emergency, and find yourself without O-rings and a decent crush washer, this will work. The O-ring kits can be found at HF or Autozone, and most everyone likely has those stores available in their area (if the Pelican sells an O-ring master kit, buy one so you have it ahead of time). Is this a ridiculous cost to pay for what's really a 30 cent O-ring and 30 cent crush washer? Sure. But it can work, and the gasket maker could be used for years if kept sealed; further, it may work in situations where the flat surface on the filter housing is irregular due to gouging from previous crush washer usage.

vstech · #8 08-31-2016, 07:33 PM

I may be able to get you an 02 setup if you want the updated dual o-ring banjo bolt...

iladelf · #9 09-01-2016, 01:36 AM

Appreciate that vstech; sent you a PM.

Unbelievable. Just happened to stumble into this Youtube vid online (guy is funny!); what he does with a bolt needing a crush washer is simple genius. One of those "why didn't I think of that?" ideas. Check it out. He even tests it; no leaks.

https://youtu.be/_5LWcTVeWR8?t=492

vstech · #10 09-01-2016, 06:23 AM

I wouldn't think that solution would work, but crushed together must seal the coil...

iladelf · #11 10-10-2016, 06:59 PM

Ok, so after driving this ride for about a month since my repair, The Right Stuff is holding. However, a word of caution about The Right Stuff. The "stuff" in and of itself is magical, but the tube it comes in (at least mine anyways)? Ain't worth a hoot. Tried to use it the other day for a seal on a bathroom fixture, and when I went to use it (it still had flow and hadn't hardened), the frickin' top simply broke off. My can was supposed to work in a "Cheese Whiz" fashion, but as I understand it, the newer can design I had sometimes has problems like that. So...$14 for a one-time fix. Indeed it works, but next time, I just might try the "copper coil" repair mentioned in the Youtube video.