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'95 993 / 2011 F150 Raptor SC / Land Cruiser D4D V8 / 500 SEC
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Discussion Starter #1
I tried to replace the fuel filter yesterday. I have the 2-pump version.

For the life of me I can't fiure out how to get the old filter out. I can see 2 screws that clamp the pumps. Above the pump I can see a screw that maybe clamps the filter, but it's stuck and if I try to force it I'll wreck it for sure.

So what's the MO here ? Just clamp off the fuel line from the tank, loosen the 4 nuts and take the whole assembly out ?

I'm not too happy right now.

Thanks,

Pete
 

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'95 993 / 2011 F150 Raptor SC / Land Cruiser D4D V8 / 500 SEC
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Discussion Starter #3
Doesn' look anything like my setup, unfortunately. I have two pumps, side by side, the filter on top of that, and the accumulator (all metal) on top of that connected via a steel fuel line.
 

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'82 Euro 500SEL, '85 Euro 500SEC AMG WB Cabriolet,'86 Euro 500SEC RUF
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Peter,
Better to drain the tank first. then disconnect the fuel lines to avoid a "Petrol Bath and possibly wrecking the fuel line. The bolt between the pumps and the accumulator does have to be loosened. I would(do) take the whole assy out if I cannot loosen the center bolt easily.
I'm getting ready to do the same job to Mosby.
 

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2013 MINI Copper S Clubman, '84 300CD-weekend car
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Doesn' look anything like my setup, unfortunately. I have two pumps, side by side, the filter on top of that, and the accumulator (all metal) on top of that connected via a steel fuel line.
Okay, could you provide a chassis number?

It'll start with 126.xxx. Engine number also, such as 117.xxx.
 

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1986 420SEL/1995 E300D/4 BMW’s/2 Vanagon’s
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1,026 Posts
Its probably going to be difficult without removing the whole assembly if there bolts are frozen. I had to remove the assembly and drill out the bolts and replace them. Its not that hard to remove, but, as one poster said, drain the task or have it almost empty with a bucket ready. Also, get new crush washers for the lines when you re-install. Don't forget to disconnect the battery as a precaution. I would replace the bolts with stainless steel so that in the future you can hopefully avoid this whole process again.
 

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1987 560SEL Astral Silver/Silver blue leather,Michelins,SONY
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820 Posts
I keep seeing this reccomendation to "drain the tank" before replacing fuel filters and pumps. Are you telling me that just grabbing that line with a rag and then stuff something in/over the connection is too hard to do? I had new pumps and filter installed at my Chevy dealership and it took less than an hour for a guy who had never seen one before.I must be missing something.
 

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Daily: 2000 Kleemann Supercharged CLK 430. Seductress: 1988 Jap AMG SEC Widebody
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^^ +1 on battery disconnect and replacing the copper seal rings/washers at the metal fuel line union on the one end of the filter - they're cheap even from the dealer and you may not be able to get a leak free seal reusing the old ones - also, I don't know the torque spec on those but when I did mine it took alot of tightening to get a complete seal.

In lieu of draining the tank, if the rubber fuel lines that feed the pump/filter accumulator system are not brittle, clamping them off with some vise grips with buffer material between the teeth of the grips and the hose for the relatively short period of time that you would need to is an alternative - if they're brittle, consider replacing them. It is also useful to take the fuel cap off at the filler door to relieve pressure in the tank - but put it back on once the pressure is relieved before you start working to control fumes in your work environment.

Lastly, if you're going to try to get the filter clamp screw off without the hassle of removing the whole assembly, try giving the little bugger a controlled shot of PB Blaster and letting it sit for a while. In my experience, that stuff works wonders on frozen joints.
 

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1987 560SEL Astral Silver/Silver blue leather,Michelins,SONY
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Yes, I believe that is what the young fella did to change mine: clamped things off. He did two new pumps and filter in about an hour, I handed him the new copper "crush" washers and went out and had a coffee and donut.
Far as I know the kid had never been under a Benz in his life until then, but I chatted with him a bit before he started.
No big deal.
I didn't relieve pressure by loosening fuel cap but I should have and that is solid advice.
 

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'95 993 / 2011 F150 Raptor SC / Land Cruiser D4D V8 / 500 SEC
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Discussion Starter #10
I'll just take the whole thing out then...

Rmac58 : thanks for the effort, but you can stop looking. I haven't found a workshop manual for post 86 Euro's. They exist, I've seen them on WIS. But so far no luck.

What's all his about draining the fuel tank ? Put a fuel line clamp on it (5$ at the motorfactors) and stuff a rag in the hose. Done it like this for 40 years. Different rag though...

Come to think of it...there seems to be a lot of pressure acumulating in the fuel tank. Is this normal ? Isn't there supposed to be a bleed hole in the filler cap ?

Peter
 

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'91 560SEC, '98 SL500
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I just did this entire rebuild recently. I did not drain the fuel tank, I just used a bolt to prevent fuel from leaking out and I removed the entire assembly with the pumps, filter, bracket and accumulator. I am glad I did this as it gave me the opportunity to closely examine the condition of all the components including the fuel lines on my table rather than under the car.


Hope that helps.
Yasin
 

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'95 993 / 2011 F150 Raptor SC / Land Cruiser D4D V8 / 500 SEC
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Discussion Starter #13
I just did this entire rebuild recently. I did not drain the fuel tank, I just used a bolt to prevent fuel from leaking out and I removed the entire assembly with the pumps, filter, bracket and accumulator. I am glad I did this as it gave me the opportunity to closely examine the condition of all the components including the fuel lines on my table rather than under the car.


Hope that helps.
Yasin
Yup, that's the ticket. I STILL don't see the bolt that loosens the filter though :surrender:

Pete
 

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MB 420SEL 1986-Bought in 2010, MERCURY VELLAGER-1995, NISSAN MAXIMA 1996, Buick Lesabre 1995
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Yup, that's the ticket. I STILL don't see the bolt that loosens the filter though :surrender:

Pete
When you buy a new filter or if you have new filter, just open the box and look at it you will know what you are looking for. You will not have any problem in replacing the filter but it will be difficult to attach the fuel line air tight. Use correct size copper or aluminiam crush washer on both side of the nuts otherwise you will be pulling whole out again to make it leak proof. Guess what! How do I know?

Sahai
 

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300GD 5 dr 1987, W126 420SE, W126 560SE
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1,676 Posts
I tried to replace the fuel filter yesterday. I have the 2-pump version.

For the life of me I can't fiure out how to get the old filter out. I can see 2 screws that clamp the pumps. Above the pump I can see a screw that maybe clamps the filter, but it's stuck and if I try to force it I'll wreck it for sure.

So what's the MO here ? Just clamp off the fuel line from the tank, loosen the 4 nuts and take the whole assembly out ?

I'm not too happy right now.

Thanks,

Pete
Yes peter the screws you see are the ones to loosen the clamp, however they are just 'philips' heads and when they get stuck with rust they are a nightmare to remove.
This might lead you to having to drill them out.
I did manage to crush up the old filter enough on my friends car to take the pressure off the screw. I replaced it with a more easily removed hex bolt and lots of antiseize.
 

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'95 993 / 2011 F150 Raptor SC / Land Cruiser D4D V8 / 500 SEC
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Discussion Starter #16
however they are just 'philips' heads and when they get stuck with rust they are a nightmare to remove.
Indeed ! I am taking the whole shebang off tonight and will show no mercy for these stupid srews !
 

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1999 E320, 2000 E320, 2003 E320 Wagon, 2005 C230K SS, 2010 Accord LX w Eibach & Koni FSD's
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Its not just a Philips screw! The bracket is NOT threaded. There is a nut on the other side. I found this out after I cutted the screw off with a pair of dikes.
 

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1986/1990 W126
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I'll just take the whole thing out then...

Rmac58 : thanks for the effort, but you can stop looking. I haven't found a workshop manual for post 86 Euro's. They exist, I've seen them on WIS. But so far no luck.

What's all his about draining the fuel tank ? Put a fuel line clamp on it (5$ at the motorfactors) and stuff a rag in the hose. Done it like this for 40 years. Different rag though...

Come to think of it...there seems to be a lot of pressure acumulating in the fuel tank. Is this normal ? Isn't there supposed to be a bleed hole in the filler cap ?

Peter
There is meant to be some pressure, but not too much. There are specs somewhere for how much there should be. You'll see the little valve that controls it near/above the rear axle. If I were you I'd replace it as a matter of course, they can get blocked and ruin your fuel tank. Very cheap part at the dealer.
My car has been great apart from going through two fuel tanks because of this. (Actually the lines further up somewhere are blocked too so they are disconnected now after the valve.)
 

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'95 993 / 2011 F150 Raptor SC / Land Cruiser D4D V8 / 500 SEC
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Discussion Starter #19 (Edited)
Oh god, who thinks of this crap :bash: . If I ever meet the idiot that thought this up I'm going to have a piece of him or her, I swear !

I need to do a delete on this. I think I just found out what causes my cold start problem.

It's made horribly. The fuel return line will cause the tank to pressurize. That pressure needs to bleed somewhere. Looks like it's supposed to force the gas through the carbon filter and out into the air. If something gets blocked the line will rupture...if you're lucky. If you're unlucky the tank will indeed go boom.

I can't determine, however, where hose (8) connects. It should be on top of the tank or in the filler neck. For now I think I'll just drill a small hole in the filler cap.
 

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1986/1990 W126
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If you do that, the car will stink badly of petrol unfortunately, in the cabin too. The filler caps are meant to be pressurized.

I'd suggest you consider just disconnecting the hose '8' that is below the vent valve '5'. And pop a new check valve on, then you are sorted for now. I think the valve itself was like £6 or something. the vent valve will be venting to the air below the car but I haven't found any problem with that at all.

I dont think that tank can go boom, the cap is meant to release pressure before it gets critical. What mine did due to the blockage, was vacuum itself smaller. Seriously, the car was costing less to fill up so I thought petrol prices must have gone down. Lol.
Apparently they will go quite small, as the pumps are quite strong. Oddly the car still drove really well.
Second time it did it, you can imagine I was well chuffed :) Thats when we realized the line was blocked further down to the charcoal cannister.

Obviously the system is meant to feed the fumes from the tank into the intake during certain conditions via the charcoal cannister, which I imagine was meant to save a little fuel, but if so it must be so marginal.
 
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