tool to remove gass gauge sender from tank 300-E
 

One of the family members has a 1987 W124 300-E. The sender to the tank and gas gauge stopped working and last weekend on my way to get gas I ran out of gas and got stranded till AAA could come along.

Well I am going to fix this bugger once and for all. What is the part number for the special wrench used to loosen the sender from the tank in the rear of trunkafter I pull away the carpeting?

I do not know if it can be cleaned and it is just sludge build up on the sender. But I will not drive this car till I know for a fact the gas gauge works.

Recommendations welcomed.

Bob Geco

I am curious!! But don't you need to drop the gas tank to get at the sender? I didn't know you can get to it from inside the trunk. I mean if in fact you can then I think mercedes did a very big favour to the community.

Fuel level sender unit
 

Bob,

I'll have to spool up the FSM disc to see if it lists the "MM" of the wrench.

You'll want to be extra especially careful when you pull the sensor unit out
and disassemble it.It uses two very fragile wires to "sense" the level of the
float!

'About 1996 I managed to solder one of the wires back on a 240D.'Only
because my Scots... Irish... German... Grandmothers attended Mass on a
regular basis.

The sensing unit is inside an aluminum tube , which only adds to the likelyhood
of Algae buildup.

UPDATE: the FSM only lists tightening torque of 40 NM

REPLACE the gasket(s) when you do remove the sender.

MINE were plastic headed [and Rudolph, forgive me I used a GENTLE twist
from a pipe wrench to loosen them.]

Special wrench? I just used a plumbing wrench. The fuel tank is located in the trunk, not underneath the car, so you just need to remove the carpet wall.

Gasoline tank sender removal
 

I am not getting any sleep. I just went through a stack of manuals for the W124 and none discribe in detail the removal process other than an almost empty tank and removing the netative battery cable. now I know I saw this information some were , I cannot fine my Cds from MErcedes-Benz on the car may be that infomation is in their.

This is driving me crazy, it should not but I got my mine rapped around the problem and want to tackle it correctly.

Bob Geco

It's not a big deal. The sender is at the top of the tank so the fuel level doesn't have to be all that low. I R&R'ed these in both our 124s and didn't buy a special wrench, although I don't remember now what I used.

I thought the hardest part was getting the liner out of the trunk to expose the tank.

Just relax and do it.

all you need is.......1 13/16 inch socket with an adaptor to 1/2 inch drive and 1/2 inch rachet.the cover nut unscrews and then you can withdraw the sending unit.make sure that you dont lose the large o ring or you will be smelling gas fumes for a long time.do yourself a favor and put in a new one.good luck.

Hi, i have a '99 E320 (W210). Would appreciate any help on location of fuel sending unit (in gas tank or in fuel pump), any special tools required, and instructions on replacing.
Thanks in advance for your help.

I have read a 1 7/8" socket will fit but I also used a large adjustable wrench. Best to have less than 1/3 fuel in tank.

Remove carpet wall (I also removed the trunk floor carpet in case I spilled some gas from the sender, which I did), unplug connection, loosen large nut, remove sender. Do a search and there is much info on how to clean the sender.