Hi,
A friend of mine has a toilet with closely coupled system and overflow empties into the pan. After a fair amount of googling I think she has a bottom-supply torbeck type valve. We have carefully taken the thing apart and checked the diaphragm for tears or build up of crud. I have put it back together in the same order is I dismantled it and didn't cross threads etc. All I have succeeded in achieving is the valve does not shut the supply off at all when the float is up and the cistern overflows at a much higher rate. At least we understand (sort of) the problem - but for now the toilet is out of action - I have shut off the supply to that toilet.
Now I have seen many wordy description of how these should work but does anyone know of a link to a site that shows exactly the operation and the areas where the valve can fail? The only part that seems relevant to creating the seal to shut off the supply is the diaphragm valve with a tiny, delicate pin type thing that passes through the middle of the diaphragm. The following seems a pretty good image of the diaphragm
Could the problem be something to do with the tiny pin hole in the top of the valve body?
Can anyone provide any more info on the operation of these or advice on replacing diaphragms or replacing the whole unit?
Thanks
Clive