blisters on flush valve seal

[davidwf]

Had a leaking flush valve in the cable operated Fluidmaster drop dual flush valve in the toilet cistern that initially turned out to be some limescale debris stuck between the flush valve (drop valve?) and its seat.....
After removing the unit and cleaning it all out I noticed what I can only describe as some quite large - about 3 to 8mm - "blisters" on both sides the silicone washer that seals the outlet at the bottom of the valve, I carefully pierced them with a fine needle and water came out
After re-assembly it all works and seals OK.....but what on earth would cause the blisters under the surface of the washer??

 

[Chuck]

Must be some sort of manufacturing defect. Are you sure it was 'water' and not uncured silicone that came out?

If it was water, injection mouldings that aren't done just right often have vacuum voids or air bubbles. If the defect extends to the surface there would be a path for water to get in.

If you report the problem to Fluidmaster:

Contact Us

Fluidmaster technical support agents help thousands of homeowners each year fix their toilet problems.

www.fluidmaster.com

they'll probably be able to tell you the exact cause and may send you some replacement seals as a 'thank you'.

 

[Chuck]

Duplicate post due to forum server acting up.

 

[ShaunCorbs]

Common issue needs changing eg replacement washer

Screwfix pn 25438

Geberit had the same issue