I went to replace my fuel filter and noticed that the fuel damper connected to it was incredibly rusted and would catastrophically give out any day. As such, I figured I'd order a new part from Mercedes (p/n A1704700316), but was advised this part has been discontinued. No one in the UK had it in stock. Another member here checked for me in the US and there was also no stock there. I called a Jeep dealership in the UK and they were able to track one down in Italy sitting on the shelf somewhere, but wanted £250 for the part.

Although fuel dampers are relatively common on older cars, most are located on the fuel rail. It's rare to find one in-line with the fuel filter. Someone on the Facebook group noted that an early 00s Subaru Impreza had one of these, so I took a shot in the dark and ordered one up (p/n 42086FE000). The cost was about £50 and there are no stock issues (https://www.importcarparts.co.uk/pro...ly-42086fe000/).

I finally got around to installing it, as well as all new fuel hoses on the fuel filter, and I can say that it works flawlessly. I've done about 100 miles since install and the car runs identical to how it used to with no codes/lights. At this point, I'm comfortable recommending this as a permanent fix for a part that has been discontinued.

I'll share some photos of the before and after, as well as a diagram that gives some advise on what hose sizes you need if replacing hoses. The install was fairly straightforward, but if you're replacing the hose that goes to the tank, a fair bit of fuel will come out when you pull the hose off. There's no way to stop it other than by putting on the new hose, so my recommendation is to have everything connected up to the new fuel filter and pull the tank hose last. My bracket was also extremely rusted, so I had to end up drilling the screw out, as the head just disintegrated when I used a screwdriver.



Original fuel damper about to disintegrate


Also note how bad the hoses looked, hence why I also wanted to replace these.


Finshied job with new hoses (aside from hose to charcoal canister, as it's just a vacuum line) and a new bracket (as mine was very rusted). Bracket is p/n A2024711341 and the screw is p/n N000000002053. Fuel pump was not touched.


View of the Subaru fuel damper during install.


This is someone else's diagram originally (from this site) and it's the best view I've found of the complete unit. I've added my comments in red for each of the four hoses going to the fuel filter.

 

This is a great write up. I will be soon rebuilding everything under the car regarding the fuel pump, filter, and vapor canister. Thank you!

 

.


GREAT DETECTIVE WORK! If Dave (180) was still here, I would ask him to make this into a .pdf and a sticky (since the part is a suitable substitute). I know of no-one else who can do this, so can a MOD see if this can get done?


.

 

I am due to change the fuel filter this summer. This would be an ideal time to check out the damper as well. Many thanks for the info. I am in the UK so getting parts can be a nightmare.

 

Glad it's helpful. I can confirm that after a couple thousand miles of use, I've had no issues from running the Subaru fuel damper, so the part definitely works.

 

As an aside, what condition were the other hoses. I am thinking while I am working in that area, change all the hoses for piece of mind. Yes, the difficulty will be sourcing new items. Any guidance is appreciated.

 

Check this post and you will see what you will need: https://www.crossfireforum.org/forum...goolie-10.html

Here is the hose: https://www.crossfireforum.org/forum...goolie-10.html

 

Two weeks past I replaced the hose that runs from the fuel tank to the fuel pump. I ran the gas low and drained four gallons out of the tank before unscrewing that house and replaced it with a new MB 170 470 04 75. Waste of time. The hose was in very good condition with very little deterioration. I have drivien 18 wheelers and delivered gasoline and diesel fuel making a living On one truck a suction hose internally had deterioated to the point the fuel was almost black on discharge. With our hose being 20+ years old I was concered something similiar may be happening, but that was not the case.

I replaced that house on one of my two Crossfires. I won't do it on the other.

 

Svengoolie always has really great writeups. I actually hadn't seen that one before attempting the job for myself, so that would have been very helpful. My hoses did not look to be in amazing shape, and as they all need to be disconnected to do the job, I just planned to replace all of them. I worked with my local MB dealership parts dept to get most of the parts. The diagrams are below, with pricing and availability from the parts dept., but note that some of the hoses are no longer available. Some of my brackets/bolts were also in bad shape, so I ended up with most items from these diagrams, but it may be different for someone else depending on the condition. I've made some additional comments after each diagram that is helpful.



In this diagram, the hose you definitely want to get from MB is hose #120. It goes from the fuel filter up to the fuel tank. This hose is a different diameter at each end, so I have no idea how you would source this independently of a MB part. For hose #100, instead of paying MB an extortionate price for a meter of hose, I just purchased some 7.5mm fuel hose from a wholesale website. This hose is also the same size as the hose on the fuel damper, so if you happened to find a damper independently (and don't go with my ready to go Subaru option), then you can use the same bulk hose for #100 here and for #40 in the diagram below.



Hose #70 is just a breather/vaccum hose, and mine was still fine, so I opted not to replace this one. The hose is no longer available from MB and I didn't have a correct size hose to hand to use. However, you could easly replace this at any time in the future, as no fuel flows through it. Disregard the comment above about hose #30, as it doesn't make any sense, as all R170 SLKs were petrol. I'm not sure what the parts guy was talking about. The fuel damper + hose is what goes here anyway (part #40).

I hope this helps a bit regarding what parts you may need for hoses. I should have included this in my original post, so apologies for omitting it.

 

Hi, I'm the guy who does the "Svengoolie" write ups.
Thank you for the diagrams, and descriptions, they are good to have for reference.
I assume that you used high pressure clamps and that the fuel hose that you bought is rated for high pressure. When I first did my fuel pump and filter I tried regular fuel hose with worm screw style clamps.
The high pressure caused leaking, so I replaced the lines with Mercedes hose and high pressure fuel clamps (see picture below).
Cheers,
John

 

That is a great call out with the bulk hose that I bought. What I used was specifically intended for high pressure fuel systems. I can't recall exactly where I purchased it, but there are many online places that sell this type of hose in bulk. I think it was about £6 for a meter, so much better than the £27 MB wanted to charge me.

Regarding clamps, I opted for the OEM single-use crimp style. As much as I hate taking them off, I must admit that they are highly effective. The reusable style of these that you opted for I've actually had issues with on my other car (on a coolant line), so I just didn't want to take a chance with the Crossfire. That being said, the Subaru fuel damper I bought came with hoses attached and it had the same reusable style of clamp that you used. I just left them attached and it has been fine so far with no leaks. At any rate, I agree the worm stype clamps are not a good choice for this particular application.

 

@Bozman52 Many thanks for the "shopping list". Thanks for confirming the parts are MB dealership prices and that the diagrams are from the SLK drawings held by the dealership parts dept. We can then compare them to our Crossfire drawings and covert across as required. I.e. the fuel filter is item 20 on your drawing, but item 17 on the Crossfire drawings?

Many thanks to everybody else as well.

Now that I am back from my holidays It looks like it going to be a full change of everything associated to the fuel dampener and associated hoses.