Fuel Sender leak W202

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mr. shr

MB Enthusiast
Joined
Apr 22, 2004
Messages
1,879
Hi guys,
I've noticed that the nearside fuel sender on my 202 is dripping.

It's the metal disc part in the middle. See pic.
I tried to nip it up with a TX45, but in doing so I discovered it isn't a TX45!!! And I've probably damaged it!!

Can anyone advise on how I go about fixing this please? Do I need to change the whole sender?
 

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The small metal plug looks to be the access point for the MB pump. This is where they pressurise the tank when emptying.

I would first check the other pipes connected to the same fitting, diesel has a habit of tracking across from one place to the next easily.
 
The alloy cap is where the fuel tank is drained, there is a rubber o-ring behind that if you are 100% sure it's that then buy a new cap from Merc, other than that if it's ever had tank sender units the big silver ring with 4 holes in might not be tight enough if the correct tool wasn't used, also check rubber pipes as they perish over time and the pressure created by the petrol pump will force a fine jet out of cracks.
 
The small metal plug looks to be the access point for the MB pump. This is where they pressurise the tank when emptying.

I would first check the other pipes connected to the same fitting, diesel has a habit of tracking across from one place to the next easily.

Mine's a petrol.
It certainly looks as though it's coming from this point.
 
The alloy cap is where the fuel tank is drained, there is a rubber o-ring behind that if you are 100% sure it's that then buy a new cap from Merc, other than that if it's ever had tank sender units the big silver ring with 4 holes in might not be tight enough if the correct tool wasn't used, also check rubber pipes as they perish over time and the pressure created by the petrol pump will force a fine jet out of cracks.

I've had the car about 6 years and never had a sender changed. I wouldn't be surprised if they are both original. Car is nearly 14 years old.

I'm just waiting to run the tank down so that it's near empty before I go about removing this drain plug.
It's an 8 mm hex, right?
 
Pretty sure it's 8mm yes, take it out irrespective of tank level, there will only be a small amount of fuel come out, imagine it to be like a tyre valve, nothing comes out until you press the spring loaded centre.
 
Tried this morning but I can't get the drain valve to move. I think my earlier attempts witht the Torx 45 bit have ruined the head.

Think I'm gonna have to change the whole sender.
This will involve buying the special tool, which will get used once and then sit in the garage gathering dust.
 
No need to buy the tool. Just use a punch and a hammer.

Drain the tank from the fuel rail at the front. Bridge the fuel pump relay and pump all of the fuel out. DO NOT undo the sender without pumping the fuel out.

Second thought. Use a sharp chisel on the cap that is leaking to undo it.
 
No need to buy the tool. Just use a punch and a hammer.

Drain the tank from the fuel rail at the front. Bridge the fuel pump relay and pump all of the fuel out. DO NOT undo the sender without pumping the fuel out.

Second thought. Use a sharp chisel on the cap that is leaking to undo it.

Ha ha.
Olly, you always make stuff sound so easy.

So you think I stick with trying to remove the drain cap?
I tried to clamp a pair of mole grips on it and turn but it wasn't moving.
 
Will have another go at removing the drain valve tomorrow.
Any other ideas for removing it.

If I get it off, I'll replace it with a new one, so doesn't matter if I damage it.
It's just difficult to get any leverage whilst laying on the floor.
 
Quick update:
Managed to get the drain plug off!!
I used an impact driver (which didn't seem to move it at all), but combined with the use of a hex bolt with long lever and it suddenly started to move.
I suppose the repeated shocks from the impact driver must have worked it loose and then the hex on a long lever was just enough to get it going.
Once going, I could simply spin it off but hand.

Now, only a few drops came out with the plug removed (as Auto-mobile suggested). The seal ring is spilt in a couple of places so defo needs replacing.
But here's what I don't get:
If loads of fuel didn't pour out when undoing the drain plug, then that suggests there isn't supposed to be fuel immediately above it. Therefore, how can it be leaking from the drain plug?
Kind of got me worried that this isn't the point it's leaking from (although, it really does LOOK as though it is. Everywhere else seems dry).

I'll go ahead and replace the drain plug and seal to see how goes, but confused as to how fuel could even come from this point.
 
i am a victim of the same leak that ur trying to fix whenever i full my tank it wud leak as hell i jus use nail glue n jus glue everywhere n no more leaks 4 me...whats a nail glue.....nail glue comes in a little pink bottle where female use to glue there fake nails unto there finger nails its the strongest glue out there and u can use it on anything i use it on my bumper and it still holding it together sameway and alot of other things:thumb::thumb:
 

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