Leaking McAlpine ubend connection to Burlington waste basin

[Bettyboo]

Hi

My basin waste became blocked and so I unscrewed the McAlpine u bend , when I went to put it back I found it was leaking from the top of the ubend near the sink . As the seal was a bit worn I bought a whole new McAlpine identical replacement ubend from screwfix but it has made no difference . I have tried tightening it at different degrees and it continues to leak . I have attached a photo . I am trying to attach it to a Burlington basin and sink hole , please can you advise me what to do

Thanks!

Betty

 

[ShaunCorbs]

Ptfe the new one round the rubber and top spigot/ upstand on the trap

The issue is it’s not sitting spot on in the centre if you look / feel there’s quite a bit of slop in the chrome to trap connection so hard to get it spot on in the centre adding ptfe to the upstand will lessen this and centre it better

 

[Bettyboo]

Thank you I will give it a go