Huco fuel pump need priming?

[p.hammar]

Hello
I have taken the engine out of my sailboat and I am now in the process of emptying the diesel tank in order to remove it. I have an electric fuel pump with the following information on it:
Huco (actually with a german "ü" but everyone seems to accept Huco)
13 3010 14V
e1 023199
226

When I connect the pump to a battery in order to empty the tank, it only sounds, doesnt pump any diesel out. It sounds healthy enough (knocking, clicking sound) and has pumped fuel to the engine without ever failing for many years. Incidentally: I know that there is air in the system now, because I stupidly removed the incoming fuel hose to the pump and put it back before I tried the pump, for reasons beyond this issue. Do I need to prime the pump in some way to get the diesel flowing? How?

Kindly
Per Runhammar

[noelex 77]

The vacuum oil extraction pumps (Pela and the copies) work well to prime a diesel fuel line. The small tubes are usually a suitable size to a push fit inside a flexible fuel hose.

[GordMay]

HÜCO fuel pumps:
The pump is self-priming and stops when no fuel is needed (energy saving)
Needs not necessarily be fitted below the tank (self-priming).
Part No: 13 3010
Delivery capacity 130 l/h, Pressure head 0.15 BAR, Suction head 0.2BAR.
➥ Gower & Lee HUCO Pump Page