Fuel Tank Venting - Identify Lines

[Benz280]

Have the smell of fuel in the trunk. Have not been able to identify any leaks in the lines but would like to understand where each of the vent lines go.  Do any of these lines hold any fuel ? 
Looking to identify where each of these lines go and how they function . ( The bottom line of the beige shows disconnected, in fact I was checking when photo was taken .. is in fact connected )
Color Legend : 
Yellow
Green
Beige
Red
Blue
 

[WRe]

Hi,
maybe it helps when you read the document about the Emssion Control System in the Technical Manual.
...WRe

[Benz280]

Thanks WRe,
The 2 lines that enter the fuel tank, I'm assuming one resides on the top of tank and the other on the bottom as to have positive / negative pressure ?

[WRe]

There are more explanations in the documen mentioned.

[Tomnistuff]

There is another possible source of leaks that one should be aware of on Pagodas.  The fuel level sender gasket, at least on the 230SLs which have a sealed unvented tank, can be a source of trunk gasoline smell if the cork gasket is old and deteriorated, especially if one or more of the vent lines to the emissions system become clogged with varnish causing a pressure buildup in the tank due to recirculated hot fuel.

I am not familiar with the emissions system on the 280SL but have definitely had smelly fuel vapor problems on a 230SL which I finally fixed by "plunging" out the vent tubes with a wire (mine were partially blocked), making two or three gaskets from Felpro Karropak fuel proof gasket material (to build up the correct thickness), stacking them and sealing them liberally with Permatex high temperature thread sealant (PX#59234), then reinstalling the fuel level sending unit.

Good luck.

Tom Kizer

[Pawel66]

I had a fuel smell in the trunk exactly due to the fuel sender gasket leaking as Tomnistuff is saying. Easy to check.

[Benz280]

Thanks All, that's my check for this week.
Questions, did you see fuel at the gasket ? 

[Tomnistuff]

I don't remember well enough to describe it but there was enough dampness to make it obvious that it was the source of the smell.  It is on the top of the tank so there would not be a lot, but since my tank tended to pressurize when driving because of the plugged vent lines, the vapor was escaping past the gasket under the rubber trunk mat and condensing in the sending unit recess on top of the tank.  The trunk smelled awful.  After fixing it and letting the thread sealer cure for a couple of days, I cleaned it with soapy water and a rag but it still smelled bad for a while.
Tom Kizer

[Pawel66]

Thanks All, that's my check for this week.
Questions, did you see fuel at the gasket ?

Yes, I did, when I opened/removed the big round plug in the trunk floor.