Water leaking from top of Fluidmaster in toilet

[OasisFan79]

I had a problem a couple of weeks ago with the Fluidmaster in one of our toilets. It wasn't shutting off the water properly which was resulting in the water level rising up to the overflow.

Thanks to DIYNot I was able to remove and thoroughly clean up the black washer underneath the arm assembly. This fixed the water shutoff problem.

However another problem has since developed - a couple of days ago after flushing the same toilet I noticed that there seemed to be additional water trickling into the main back unit. When the flush water cuts off the additional trickle stops.

Upon further investigation (i.e. removing the top lid and watching things as it was flushing) I could clearly see that there was water leaking out of the top of the Fluidmaster - specifically coming out of the top and going down the arm as indicated in the photo below.

I removed the washer again and made sure it was seated properly but the water still comes out.

I noticed that there is obviously the small hole in the center of the washer that the small metal pin type thing comes through when it sits in position - not sure if this is anything to do with it.

Any ideas why it might be leaking?

Thanks in advance.

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[danplumb]

For what its worth and all the trouble your having with it, just replace it. There only a few quid.

 

[OasisFan79]

Is it a simple process to replace it?

My main concern would be the water that resides in the bottom of the main unit after isolating the mains - what would happen to this when I remove the old Fluidmaster?

 

[Armo74]

Should be pretty straight forward but nothing is a simple process in this game. Isolate the supply flush the toilet then remove the remaining water with a jug and an old sponge.

 

[OasisFan79]

Cheers. I'll probably give it a go then.

It's a Fluidmaster at present - they seem to be about a tenner at Screwfix. As they're apparently universal fitting is there a difference between the Fluidmaster 400 and the 400A?

 

[hazetimesfive]

sorry, didn't look at the picture

 

[Charnwood]

400A is for the American market.
All you'll find this side of the pond are the 400, PRO400 and PRO45B.
All do the same job; fit to the bottom of the cistern, let in water, stop water.
Just variations of materials used to manufacture.