Fuel tank and fuel filter (47)

Please, do also visit Fuel pump and air filter!


Another nice car I had, a Mercedes-Benz 400E from 1993. Extremely sad that I sold it...

Another nice car I had, a low mileage Mercedes-Benz 400E from 1993. Extremely sad that I sold it...

Fuel tank

The first steps on the fuel tank, sandblasting and priming the outside was done many years ago. Strangely enough I was not able to find anyone in Stockholm that was willing to clean and seal it for me, like e.g. Renu in USA. The restoration of the other parts of the car had higher priority so the fuel tank had to wait. However, I knew how and with what to do it. I had read about Fertan GmbH in the German car magazine Oldtimer Markt so that was an obvious choice. So I ordered their tank cleaning and coating package via the web. 

 I started off with taking some pictures of the fuel tank's inside with the help of a digital inspection camera. The picture quality is not the best but at least I could take some shots and videos and see that I had rust, but not that much and, above all, no deep rust attacks in the seams between the two tank halves.

  • Rusty breather pipe in Ponton fuel tank
  • Rusty fuel filter in Ponton fuel tank
  • Rusty inside of Ponton fuel tank
  • Rusty fittings of Ponton fuel tank

After that I rinsed the inside thouroughly with the help of their product as well as sodium hydroxide. After the cleaning comes the de-rusting/rust converter product and process. The two last pictures show how I sealed the openings.

  • Products for cleaning and de-rusting fuel tank
  • Sealed Ponton fuel tank
  • Sealed Ponton fuel tank

When the fuel tank has been de-rusted and, very thouroughly, rinsed and dried it was time for their 2k coating. After applying, disperings and emptying of the coating it had dry up in a warm place and with a constant, low air flow. Thanks god for my compressor.  The coating is very thin. I had my doubts after these pictures but I sent Fertan a bunch of pictures and according to them the result was excellent and will protect the fuel tank for a long time. Othwerwise I could just have re-done the coating, with my left-overs, once more.

  • Products for coating MB 219 fuel tank
  • Ventilating coated fuel tank
  • Coated breather pipe in MB 219 fuel tank
  • Coated filter fitting in fuel tank

Then I sanded the tank's old layer of primer and put on a new, fresh layer of my normal primer. Finally two layers of 2k, glossy, black paint, as it should be, was applied.

  • Ponton fuel tank before new primer
  • Primed fuel tank
  • Glossy black on Ponton fuel tank

Believe me, there's a lot of fuel tank shaking during this process. Good traning for your shoulders. Next step will be to mount the fuel sending unit (see "Instruments and switches"), the pipes and sound insulation and then put back on the car, where it belongs.

If you're interested in seeing the sandblasted tank you can actually find it in on of the first galleries in the Rear axle article.

With the tank coated and painted it was time to add the reinforcements screws for the assembly of the tank under the car as well as new sound insulation and rubber hoses for the ventilation and breather pipes.

As sound installation I used Dynamat’s 1/2” Dynaliner. Reusing or finding new, hard ~1cm thick felt, soaked in bitumen or tar, didn’t feel like the right way to go. The Dynaliner was used for the interior as well and is resistible to water, salt, oil etc so it was an easy choice. And it won’t be visible. The Dynaliner is self-adhesive but I chose to be on the safe side and glued them with Casco’s „S9 „Super Glue“.

  • Ponton fuel tank with new and old (felt, soaked in tar or bitumen) sound insulation
  • Mercedes Ponton fuel tank with new sound Dynamat Dynalinder sound insulation

Fuel filter (47)

See the Carburetor article regarding the process and lack of photo quality and fuel pump article referred to above, regarding finishing work to be done on the aluminium parts! Maybe the wire clamp with wing nut should have been white cad instead. Well, they're not now...

Pictures are rather simple, first an unrestored filter, then all the parts restored (note, the rubber gasket between the housing and the filter jug is missing here, that's not the case now) and finally the filter assembled. Due to some reason the wing nut has turned a bit red after the yellow plating. 

  • Filter before restoration
  • All parts of the cleaned Ponton fuel filter restored
  • Mercedes-Benz Ponton fuel filter assembled