I found that the factory cloth-covered return line lasted about one year on B100 before it started to leak. As long as you keep an occasional eye on the engine area you can wait until they actually start to leak before doing anything. DOn't forget the little jumper lines back at the fuel tank.

Yes, the hard clear lines are OK, you don't need to replace them.

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

The cloth line that goes from the top/rear of the filter mount to underneath the "engine dress up cover" is already leaking (I'm assuming this is the return, but have not removed the cover yet to see where else it goes), so I want to replace that one immediately. Nothing else seems to be so far besides the oil fill gasket, but that's easy.

I'll order the aforementioned 4' of viton return line, do the leaking piece now, and peer at the rest (including back at the fuel tank) every so often.

Check your PCV system while you're under there. The rubber and plastic parts will harden and crack with the heat and the lines will begin to leak condensed oil. You may find a few of the injector wells filled with oily mess.

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

The 1998-99 turbodiesels had a simpler system; I believe the breather dumps into the tuno intake. The 1995-97 OM606NA was a disaster with all those hoses splitting into 12 little hoses (one for each intake valve). As Evan says, you end up with oil all over the valve cover. I posted pictures when I did mine, it was a real mess. See the pictures in post #10 of this thread.

Two of the oil ports were so clogged with soot and oil that they were completely blocked off. Once I defeated the EGR function that stopped.

Jeremy

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

To answer the question in the thread title, there are 3 filters. The third one is in the tank and there's an o-ring that needs to be replaced if you take it out. But unless you have extremely dirty fuel in the tank or poor acceleration, there's no need to take it out & clean it.

__________________
2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL

Yes, '98 has a much simpler PCV system than the '96/7s:




The three rubber elbows have hardened and are leaking a bit - you can see some puddling in the back corner behind the PCV.

Three of the cloth lines are clean enough that I assume they've been replaced, but I don't know why ALL of them wouldn't have been given the state of the "Black" ones.

I don't see the elbows in Fastlane, I emailed Phil about them.

Also, is there SUPPOSED to be something here? Sure looks like it, unless it's an engine hoistpoint or something. Rearmost part of the intake mani:

The part numbers for your rubber elbows are:

606 016 04 81
605 016 01 81
605 016 00 81

Although, I just replaced all of the PCV components with pieces of copper pipe, heater hose and clamps since I figure they'll get hardened up again. That should be a permenent solution.

I would order yourself 6 or 7 of each of these too:

601 078 03 86
603 078 01 41

They are the plastic thingys and rubber pieces that hold your injection lines down. I see you're missing a couple and one is un-snapped. There are more under the intake manifold too.

I've always considered the hole in the manifold as a lift point as well.

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

Hehe, Phil emailed me the EPC diagram and asked what parts I needed (even after I sent the same photo to him as well) so you're one up so far!

Crossreferencing with the detali site, I see

606 016 04 81 # 35
605 016 01 81 # 65
605 016 00 81 # 71

Ah, excellent, so 35 is the same elbow in both turbo and nonturbo cases (and the other thread says it crumbles on removal, woo hoo!) It DOES look about the same, there's just no number for this "rear" elbow on the turbo section on the diagram. Thanks.

Good eye on the clips, and thanks for the P/Ns there too!

O-ring 14 on the center bolt is staight forward.
When I removed the center bolt and old filter I cannot find O-ring 11.
I am guessing that it goes on the same bolt but Below the Hole??


Thanks
Bill

Some banjo bolts only have one o-ring, if yours only has one simply discard the other o-ring.

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

When I took mine apart, there was only one o-ring. The new filter came with two so I asked the dealer tech about it and he showed me where it was supposed to be on the bolt, and it actually made sense.

There's more of a story to this. I first installed with only one o-ring but then had a problem with hard start due to air leak in (no fuel leaking out). Thinking this was the problem, I took it apart and put the second o-ring in per the tech's instruction. Problem did not resolve.

And yes, I have replaced every hose and o-ring in the engine compartment. Can't find any leak anywhere but I'm thinking of taking the tank filter out (why?) and guess there's a check valve someplace. But I don't really think that will help either. The air gap that appears is in the line from the strainer next to the main filter. I can always see air cavitating in that line when running and have to park the car level or nose down. Nose up in the drive for more than a few hours and starting is a 10 minute starter workout.

Preventive maintenance... Should have left well enough alone...

Sounds like the oring is missing on the primary filter (the black screen-like filter). If you replaced that filter and forgot to transfer the oring from the old filter to the new one, then you will get air in your system. The new filter does not come with the oring, it must be ordered separate.

__________________
Mark in MA
05 MB E320CDI 402k Granite Grey Metallic
05 MB E320CDI 267k Black
05 MB E320CDI 232k White
05 MB E320CDI 209k Tectite Grey
99 Dodge 2500 Cummins 5sp 148k
62 Jeep CJ-6 120k

That is great! Thanks very much!

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.