酷北鼻

Fuel leak issues - some investigation & DIY (http://www.mbworld.org/forums/w211-amg/375379-fuel-leak-issues-some-investigation-diy.html)

I decided to replace a gasket I thought was giving trouble. I can now confirm it is not the gasket. Image below are the gaskets. The black one is the original one and the green one is the replacement part. I had thought that the gasket was leaking so I replaced it. Either way you are going to have to remove the sender so here are some steps as to how to do it.

http://i51.tinypic.com/qrj4ft.jpg

Below is a picture of the fuel sender. It is underneath the back seat behind the driver's side. Actually there are TWO, one on the driver's side and one on the passenger's side. Only my driver's side one was leaking! So I am only showing that

http://i53.tinypic.com/2vbu1bb.jpg

Step 1. Disconnect battery in trunk
Step 2. Remove rear seat - there are two indentations that need to be pushed in to release the back seat - I didn't take pics.

Step 3. Disconnect the plugs to the sender and fuel pump
Step 4. Remove the black fuel line - be VERY careful here not to pull too hard on the fuel line since it is rather weak plastic it flexes very easily and could break. I took the liberty of replacing the hose and added some good stainless clamps.
Step 5. Turn the black ring counter clockwise to release the sender and pump.
Step 6. Ease the fuel sender up slowly and carefully. You have to wiggle it up. Do not pull too hard, there are hoses attached inside the tank

Below is a picture of the sender out of the tank:

http://i56.tinypic.com/fdt6pc.jpg

I did not know this when I took the picture but the leak is occuring where the line is shown (above)

Below is a picture of my finger pointing at it from the top view ... after I had reinstalled it and topped up my fuel tank .... grrrrr!

http://i54.tinypic.com/ir5jcx.jpg

The place it is leaking from is where the fuel pump sits. I would see fuel pouring down from the gap the line points to.

Let me finish off my "DIY" here

Step 7. Pull the old gasket out by sliding it over the fuel sender so you do not have to disconnect the tubes inside the tank.
Step 8. use mineral oil to lube up the new gasket and slide over the fuel sender and place on the tank lip.
Step 9. slide the sender back in carefully so as not to push the gasket into the tank.
Step 10. Put the black ring back on (clockwise to tighten).
Step 11. Use brake clean as lubricant to slide the fuel hose back on (remember to put hose clamps on first). Slide on quickly before the brake clean dries.
Step 12. tighten clamps on fuel hose - be VERY careful here since the tubes are made from plastic and VERY easy to crack! just tighten to where the clamps don't rotate or slde and then snug down a little. tighten until the hose does not rotate easily.
Step 13. Hook up battery
Step 14. Start car and check for leaks before replacing everything.

Step 15. Fill up tank
Step 16. Get really angry when it leaks out of the fuel pump cap!!

So ... I am not done yet but at least I know where the fuel is leaking from precisely. I need to take a closer look at that cap to see how it is held on there.

That's all for now .. I'll upload more pics and info as I find out more. If any one else has more info to share, please do!

EDIT: I think the driver's side may only have a sender and not a pump ... maybe someone else can verify this. I did not spend a whole lot of time looking at the sender. In any case it is leaking from that cap ... whatever it is!