Fuel tank cleaning, and a few odd questions - PeachParts Mercedes-Benz Forum

TWeatherford · #1 01-03-2007, 03:29 PM

After about a two hour battle I finally got the fuel tank out of my CD. It is nice how new and nice looking it is, after 21 years. I read several threads about removing and cleaning my tank strainer, and decided to rip the whole thing out and see if I can avoid buying a 46mm socket, and clean it while I'm at it.

The first interesting thing was how much fuel came out. I had run the car down, very well down. As I came up the last few big hills toward home, the car sputtered and almost died and I didn't think I'd make it. So I figured I was pretty well empty. Wrong. 5 gallons came out

, which I was not very well prepared for, at least a gallon on the floor. The fuel gauge read nothing as well. I do have my supply and return lines swapped, could this be why? Or is a fuel tank like a transmission, a lot of it stays there

I still can't get the strainer off. Channel locks are no good, and I can't get a grasp on it with my giant, 2' long adjustable wrench. I guess I'll put some nut loosener stuff on it, and beat on it some more

While its out, I would like to clean it. Whats the best way to do this? I figured I could run a whole lot of hot water through it, and then set it in the sun or somehow apply some gentle heat to evaporate it out at the end. Actually, I could just force a lot of hot water through that strainer backwards and just leave it where it sits. I'm far too cheap (translate: broke

) to have it done somewhere, so home methods only please.

Last thing I promise. There was this egg crate looking thing above the fuel tank. It has a large yellow wire running to it. I kinda busted the plastic holder, and pulled it to the side which allowed the tank to come out. It'll go back all right, but what in the world is this for? So far my best guess is the germans put it there to fill some dead space, and make the fuel tank more difficult to get out

Thanks in advance.

dmorrison · #2 01-03-2007, 03:51 PM

Here's how I cleaned my daughter tank.

http://www.peachparts.com/Wikka/W123FuelTank

Try using a shop vac, blowing thru the tank to dry it, I did mine for 4 hours.

The Egg crate unit is your vacuum tank for the car. The tank and plastic line needs to be sealed to hold vacuum. Did you break the input nipple?? or what. Realize the tank line combination MUST be sealed and hold vacuum. If it was the mounting area, just glue it and reinstall it. If it is where the plastic line goes into the tank. As long as you can get it to seal your fine. Try a plumbing type putty for cars. Any paint jobber has the 3M putty that will hold the seal fine. Or try silicon caulk.
You do need your tank to work. To much depends on it. Door locks, transmission shift, Ac elements etc. Vacuum is very big in a Mercedes.

Dave

d.delano · #3 01-03-2007, 03:55 PM

egg crate thing is the vacuum reservoir, it holds vacuum for locks

carb cleaner and a toothbrush for the tank screen, followed/complimented by some compressed air

TWeatherford · #4 01-03-2007, 05:28 PM

cool. Ahhhh, vacuum resivour. Ok, its fine then. I broke the little plastic nut that secures it to the car, it itself is fine. All I need is a crack in that

peterhardie · #5 01-03-2007, 09:23 PM

My tech uses an alternator nut welded to a piece of bar steel to take out the tank strainer, looks like 19mm or 22mm. If you find yourself a nut and bolt that size, just use a wrench or socket on the pair bolted up tight together.