random fuel level readings

[markey b]

since replacing my sender seal, i've noticed that i'm gettin strange tank readings. i literally took out the sender, cleaned it with a cloth and put it in with a new seal. sometimes now it sits at 1/4 when its 1/2 full, but when i turn my fuel pump off (its on a switch) it goes back up. other times its ok. checked connections on the sender, the only wire i took off, and all seems ok. it was also ok this morn.

just wandering if turning the sender upsidedown could have buggered it, i only dried it off really but its annoying having a dodgy reading

[Lewis]

Turning the sender upside down shouldn't cause any problems.
You say its been behaving this morning so you may as well run if for a while and see if its ok. If not take it out again and have a nosy.
I imagine its just a little resitance track which gives a variable output depending on fuel level, probably a few wires and the resistor track to check once its out. Should be obvious if it somethings damaged on it.