I have an 82 240D with a white plastic primer pump. After using and re-tightening, there is a slow fuel drip. Tightening more has reduced leak but not stopped it. Don't want to tighten any more for fear of damage.

Is there a washer under the screw cap? If so what is procedure to replace.

It looks like the plastic body of the pump might unscrew from the metal housing.

If so should the pump assembly be replaced?

Thanks in advance.