PeachParts Mercedes-Benz Forum - View Single Post

jay_bob · #11 10-19-2012, 06:30 PM

Yes the sensor is cleanable

On 123 sedan it is under the first aid box (2 screws to remove the pan).

Hint: remove bottom back seat cushion (push in buttons lift out) upper back cushion (3 x 10 mm bolts, lift out with a helper) then lay down plastic to protect against drips.

Unplug connector and using either 46mm socket or a pair of channel locks loosen and remove the sensor tube. Pull up a little and wait for it to stop dripping before pulling out all the way...

Now using a pair of snap-ring pliers carefully remove the weird nut at the bottom then remove the bottom plates. Now very carefully slide the mechanism out of the tube. There should be 3 fine wires that are very delicate and a float with contacts that bridge 2 of the wires. The low fuel light is a set of contacts at the bottom, yours might be buried in sludge.

Using mineral spirits and extreme care clean everything. Put it back together and take it back to the car. Plug in the harness with the sender out of the tank and turn the key to pos II without starting it. With the sender held vertical, you should have the pointer on Empty and the low fuel light on. Now slowly turn the sender horizontal and begin slowly turning it past horizontal allowing the float to slide towards the connector end. The needle should rise to full and the reserve light goes out. If it is all good shut the car off, unplug and reinstall.