Fuel Tank Sender

[2052006 10]

Just removed mine and have a few questions:

 

1. Can it be cleaned up at all or re-furbed to stop the rather vague indications it gives?

2. Where in Service Box is a diagram of the sender and its fittings/seals etc?

3. When I removed it, there was, in order: the black plastic "screw" cap, the sender itself, and then a rubber seal which sits between the top of the sender and the fuel tank itself. This is all fine, but there was some sort of sealant all round the threads/bottom of the screw cap. Is this sealant supposed to be there, or has it been previously bodged for whatever reason?

 

Thanks.