Kitchen sink leak

[Calculus]

When I found water was leaking from the kitchen sink into the cupboard below it I thought it would be one of the screw fittings on the U trap or pipes leading into it. But the water is coming through a dried up seal where a circular black plastic fitting sits against the the metal sink, as in the picture.

I have put Gorilla tape inside the sink (round the gap surrounding the plughole assembly) to temporarily stop the water coming through. When everything has dried out, can I simply plug that gap (see red arrow) with Plumbers Mait, or do I have to disassemble anything?

 

[denso13]

I'd be tempted to fit a new one. The supplied washers are fine to fit on their own with no sealant.

https://www.screwfix.com/p/mcalpine-sink-waste-overflow-10/6943v

 

[just pumps]

For peace of mind fit a metal jubilee clip on the grey washing m/c, dishwasher pipe, makes a god awful mess when they fall off

 

[Calculus]

I'd be tempted to fit a new one. The supplied washers are fine to fit on their own with no sealant.

https://www.screwfix.com/p/mcalpine-sink-waste-overflow-10/6943v

Thanks denso13 but I'm nervous about the overflow pipe on that Screwfix item which looks to be integral to the plughole assembly (i.e. all one single piece). Unless it dismantles at one end or the other of the overflow pipe I don't see how it can be fitted. I also have no idea how to detach the existing fitting at the overflow-hole end. See pic attached. I can see a washer there but I don't know it all fits together. Do I prise that black cap off or rotate it? I have the Haynes Home Plumbing Manual in front of me but it says little on sink overflows.

 

[denso13]

Do I prise that black cap off or rotate it?

Rotate it anticlockwise with two screwdrivers or pliers in the holes in the overflow.

 

[denso13]

 

[Calculus]

Thanks denso13, that looks straightforward enough