1987 300D fuel tank removal? - PeachParts Mercedes-Benz Forum

Diesel Dan · #1 01-03-2011, 10:14 PM

Hi folks. I've decided to get my fuel tank steam cleaned and am in the process of removing it. Quick question: is it only held in by the four nuts accessed through the trunk, or do I have to remove the rear seat to get at something from the inside of the car? I removed the four nuts from the trunk side and the tank is not coming out. I don't want to force it and break something, and before I go through the hassle of removing the rear seat, I thought I'd ask. Thanks!

layback40 · #2 01-04-2011, 12:52 AM

Dan,
cant help with the removal but when you get it out, make sure you steam it with real hot steam on a hot day. That way it will dry out bone dry. It will give you much better results. I have done it to several fuel tanks with good results.

Jeremy5848 · #3 01-04-2011, 01:26 AM

I've had the rear seat out of my '87 300D and the fuel tank definitely does not come out that way -- there's a solid steel panel behind the seat-back. There may be screws attaching the tank to the floor of the car that have to be accessed from underneath. EPC should show all of the screws and that will help you figure out where they are located. Finally, there may be something attaching the filler pipe to the chassis.

Stretch · #4 01-04-2011, 04:24 AM

If a W124 is of a similar design to the W123 then you access the tank via the trunk. There is a lightweight panel that comes out easily on the W123.

Before you remove the tank my advice would be to get hold of a siphon pump and take out as much fuel as possible before you remove the fuel pipes from the underside.

vstech · #5 01-04-2011, 08:20 AM

yes, similar to the 123, same faux panel but the perimeter bolts do not release the tank. I'm trying to do the same, but have not gotten underneath to look what's there, but there is not anything behind the seat I could see.

Stretch · #6 01-04-2011, 08:27 AM

Well it could be just glued into place - behind my W123 tank I found some sticky foam stuff that made me think perhaps I'd missed a screw for a while. The same can be said of the rubber gasket that stops the pipes coming out of the tank from chafing on the chassis

vstech · #7 01-04-2011, 09:22 AM

I don't know yet, but I had a serious prybar on the tank, and it would not budge...

Stretch · #8 01-04-2011, 10:18 AM

Quote:

Originally Posted by vstech

I don't know yet, but I had a serious prybar on the tank, and it would not budge...

I've just had a look at a source on the internet and it looks very similar to a W123 set up. (Google) Try pushing up on the rubber gasket under the tank to work it a bit loose. If I remember correctly for my W123 I could pull the gasket out slightly which helped with its stubbornness.

retmil46 · #9 01-04-2011, 10:50 AM

Well, fortunately I got my W124 Service Library CD's delivered here in NC yesterday (ordered before I left SA) - figured I'd need them, since my other copy is a downloaded version on my old desktop.

I'm looking at the fuel tank removal section right now, for the sedan.

Recommends removing not only the paneling in front of the fuel tank, but also the right and left side plastic paneling in the trunk for easier removal.

It also shows 4 sound deadening strips attached to the fuel tank with "MB adhesive".

Besides the thin rubber sealing cup around the hose for the fuel tank screen, over on the drivers side it shows a rather thick looking rubber plug, that has the metal lines for the fuel return and tank vent check valve running thru it and sticking out the bottom. Might be you need to disconnect the vent valve and fuel return lines, then pull this rubber plug out from underneath the car, off the metal vent and return lines, to finally free everything up. Or else pull UP on the drivers side of the fuel tank, to pull these metal lines up out of the rubber floor plug.

Other than that, it should only be the "MB adhesive" and the 4 nuts holding it in.

Also mentions to remove the fuel cap and the rubber seal around the filler neck.

Diesel Dan · #10 01-06-2011, 09:09 PM

vstech, have you managed to get that tank out yet? Has anyone successfully removed a fuel tank from an '87 300D, and could share some wisdom with us? Thanks!

babymog · #11 01-06-2011, 09:31 PM

I pulled one from my first '87 300D sedan (still laying in the shop). There were a couple of hoses etc. on the bottom that kept it from coming out easily, but after taking the four mounting bolts out and disconnecting the fuel sender it was moveable. Took a while to figure out which way to twist and turn it to get the filler neck free but came right out.

cessna5354 · #12 01-07-2011, 02:56 AM

DieselDan,

I understand yours is an '87, However when extracting and installing the tank on my 123, I was not as careful as needed, and the bottom of the tank blew a small pinhole. It was rusted from within and my mechanical push/pull caused a leak.

Good Luck,

Diesel Dan · #13 01-24-2011, 05:24 PM

Thanks to all for your input! As it turned out, the tank was glued in, and just needed gradual, steady pressure to "peel" it out once I removed the 4 nuts from the trunk side of the tank. And of course I had already disconnected the hoses from underneath. The filler came out easily, but the rubber gasket around mine is badly deteriorated from the biodiesel.

I put some fuel tank cleaner in there with 5 gallons of fuel and am letting it soak for a few days and sloshing it around periodically, and will also set the tank on different surfaces to let the chemicals loosen the fungus from all surfaces. I had gotten an estimate from a radiator shop of $100+ to clean it (soak it in acid for 3 days), and decided I'd try the tank cleaner first. Fortunately I don't need the car drivable right away.

Renntag · #14 01-24-2011, 07:39 PM

Quote:

Originally Posted by Diesel Dan

... Has anyone successfully removed a fuel tank from an '87 300D, and could share some wisdom with us? Thanks!

I am about to remove the tank from my 89 300E. Not a 'D' but should have some similarity. I can take pics and share.

Quote:

Originally Posted by cessna5354

... when extracting and installing the tank on my 123, I was not as careful as needed, and the bottom of the tank blew a small pinhole. It was rusted from within and my mechanical push/pull caused a leak.

This is certainly good advice, but I wouldnt be concerned about popping a hole in a compromised tank, as I would never then reinstall said tank without a proper repair. In most cases I would think that a used replacement was the best option, repair being a last resort.

Perhaps that was a blessing?

1987-300TD · #15 06-13-2011, 02:48 AM

I apologize for opening an old post. I am endeavoring to complete this same project.

We have removed most of the fuel from the tank. We have also started taking pictures to document the procedure.

We have loosened the 4 bolts holding the tank. We have also removed the 2 lines at the bottom of the tank.

Question 1, what other issues can we expect to encounter as we remove the tank? Diesel Dan mentioned the fuel sender. Where is that located?

Question 2, where is a good place to purchase replacement hoses and a filter for the tank?

Question 3, where can I get the gaskets for around the filler pipe?

Lastly, is there a best procedure for a "Weekend Mechanic" to clean the actual tank? Once cleaned, is there a product to coat the inside to prevent this from recurring?

Sorry for the Newbie Questions! She is my first diesel. I have learned a ton already!

Thank You for any assistance!

glenn

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