Hi, The dashboard fuel gauge on my 500L Trekking 63' Reg never goes to full when filling it to full with Diesel. It goes to just under full. I'm sure I read somewhere that when filling at the petrol station when it clicks off you have to keep filling it until the fuel pump clicks off 2 more times to completely fill it.
Has anyone else experienced this with a 500L? Seems a bit strange to me but am sure I read it in the handbook!

Never heard anything like this from a family member's diesel 500l
Seem more likely a sticking sender or bad connection

Fuel pumps click off when they get some back-pressure in the hose. At that point, the fuel will be half-way up the filler neck, so it's full enough. Stuffing in a couple litre doesn't do much.. although a few times I've done it to get maximum range, like when filling up in the UK just before I head to Europe (avoids some French motorway fuel). It's easier to carry a few filled fuel containers.

Anyway, if the dial doesn't go all the way up to MAX then it's probably the sender in the fuel tank. It has a float and measures a changing resistance as the float rises and falls.

The sended is inside the tank, so probably more trouble than it's worth to remove it and give it a clean.. but if you lift the carpet in the boot (or it could be a hatch under the rear seats) and remove the connector block from the fuel pump, you might see the connections are dirty/corroded. Clean them up with some emery paper and make sure the connections are clean.. if it reduces the resistance at the connector then that'll help get a better reading on the gauge.


Ralf S.