W202 Fuel Tank Sender Leak (whats the alloy bit?)

[stevesey]

All - I have identified the source of my fuel smell - the drivers side sender is leaking. It doesn't seem to the be the seal, but the silver/alloy knob (for want of a better description) in the middle of the sender. This has an hex key hole in the middle, but is rock solid if I try to tighten it. Was wondering if anyone knew what this is, some kind of plug, which could be undone and re-sealed?

 

[Ellsy Tanners]

Its a plug for a special tool which screws in to drain the tank down. it has a rubber o ring if i remmeber but doubt it could be bought of mercs seperate.

Once undone it shouldnt leak form the hole. as the tool screws up and releases a valve to drain it down.

You should be able to find a rubber o ring to fit, if not a new sender unit may be required.

 

[stevesey]

Once undone it shouldnt leak form the hole. as the tool screws up and releases a valve to drain it down.

Thanks - so if I undo the plug I'm not going to get soaking in petrol!

Hmm - if there is a valve why's it leaking now! Duff valve? Or is the value not a perfect seal in the first place? (That is good enough to stop the contents pouring out, but will still let some fuel through to the plug).

 

[Ellsy Tanners]

in thoery if the valve is functioning correctly there will be very litle come out, if not it may leak, undo very slowly with a bucket to catch leakage, then you should be able to judge how much is going to come out the more you unscrew!!

 

[rpe2]

Hi,

I have replace the seals on 2 W202's now. to be on the safe side. I have always done it when the low fuel light is on the dash.

MB supply a seal for this, don't use any old seal as it may not be suitable/ durable enough to deal with petrol.

Regards

Richard

 

[stevesey]

That'll be part no: 2029970245 according to the russian site (waiting for my ebay service manual parts catalogue DVDs to arrive).

 

[mr. shr]

How did you get on with this?
I have the exact same problem in that the shiney metal/alloy bit (as OP describes it) is dripping with petrol.

How do I re-seal it? Does the whole sender have to come out, or do I somehow just remove the metal/alloy bit?