leak from new fluidmaster 400

[PHIL269]

Hi
If anyone can give me any advise on how to stop the leak please ?

I have just installed a new Fluidmaster 400 float valve bottom entry brass shank.

It is now giving me a drip every 15 secs from the bottom white plastic washer which fits onto the cistern.
I made sure the rubber washer was put on cone end facing down inside the cistern but maybe I tightened it too much, worried about untightening now in case leak become worse.
Should I remove the valve and reinstall and should I have used any sealant though the instructions says no sealant should be used.

Thanks for any help please

Phil (feeling worried about the leak now and what to do)

 

[HERTS P&D]

Nip it up a bit more.

Andy

 

[PHIL269]

Thanks but feel like I have tightened it too much already ?

 

[HERTS P&D]

Take it off and refit it.

Andy

 

[PHIL269]

Any tips please heard good to put some fairy liquid on rubber washer maybe to create a better seal ?

 

[Elkato531]

As Andy says, refit it. Make sure the inside of the cistern where the rubber washer sits is clean. Don't lubricate the washer as this can cause it to squeeze out if over tightened. I don't think I've ever had one of these leak so its likely to be just a case of something stuck under the washer.
Also check there are no hairline cracks in the cistern.