Fluidmaster 400UK Bottom entry valve seals

[Ouch77]

Minor rant, but this might help someone in the future.

Toilet cistern stopped filling saturday afternoon. Took a look inside, opened up the valve and the little rubber seal inside was perished and had split a little. 20minutes on Google suggests that the seals are available as spares, which would be easier and less messy than replacing the whole valve assembly.

Place order with screwfix and collect sunday morning.

Fit new seal, valve now doesn't shut off.

remove and refit several times. No joy.

Examine old and new seals in detail to find they're subtly different in depth. New seal isn't deep enough to bear on the feed spout to shut the flow off. Further web searches and examination of the valve shows up that it's a fluidmaster Pro 400 which is only available wholesale, seals for those (which might, or might not fit) are available from some wholesalers (not open on a sunday) and cost nearly as much as a whole valve assembly.

Back onto the web to order an entire new assembly for pickup that day. Drained cistern, mop up mess with old towels, fit new assembly (a regular fluidmaster 400UK), refill and test, happy days.

Though it turns out that the seal in the 400UK that I just fitted is slightly different again.
urgh. why can't they either use 1 part for all applications, or make a better distiction between the marketing of the different parts?

Moral of the story: a Seal to fit a fluidmaster 400 might not fit a fluidmaster 400.

 

[Elkato531]

Don't think I've ever changed the washer on a fluidmaster fill valve. Not worth the faff as the replacement valves are cheap.
For future reference and hopefully won't be too frustrating given what you've been through, but these fill valves can be changed without draining the cistern.
Turn water off
Lift adjustable stem locking ring
Lift off valve leaving lower stem in place
Replace with new top section, adjust to correct height and push locking ring down
Turn water back on.
Probably 10 minutes including cup of tea.

 

[Madrab]

Must agree - even then, all I usually change if fluid master already there is the top half. Means you can change the fill valve without upsetting the feed or cistern. Water off, hand down and snap up the grey locking ring and pull the top half up and off, replacement is just a case of push the new top half piece onto the bottom shank to the desired height.

Water on and jobs done.

 

[Ouch77]

thanks for the tip chaps - it will come in useful for adjusting the fill height as the cistern isn't big enough to allow me to rotate the assembly once it's fitted..