Leak On Toilet Pipe

[dunnitall]

Help please.

Small leak (drip) on pipe going from cistern where it flushes the loo into top of toilet, leak is near the toilet end after flushing. Can't understand why it should be leaking from there because surely there shouldn't be water in that pipe ONLY when you flush the cistern but it's dripping after the loo is flushed not before then continues for a while. Shouldn't there be a stop or valve or something that shuts off after flush completes or else there would be water constantly dripping into the toilet bowl itself if the leak was sealed?

Would appreciate some opinions as to where the fault would lie, cistern as well as pipe, though I realise if there is a leak on the pipe anyway it would have to be fixed? I'm not a DIY'er but just need to know the logistics of it if anyone could explain to me please. Many thanks.

[The Builder]

You have the older type of separate cistern & pan, connected by a flush pipe.
The leak is either where the big plastic backnut tightens up under the cistern (rubber washer inside), or where the syphon is fixed to the cistern itself.

Syphons are quite crude, simple devices. Even after a flush, there will always be a dribble of water left that runs on. If it's a lot, then just replace the syphon. They're not at all expensive.

The other thing is that your older type syphon has been replaced with a modern type that incorporates the overflow. In that case, the float level may be too high, and water is constantly overflowing into the bowl.

[dunnitall]

Thanks Builder, yes it is the older type. Leak itself isn't running down pipe from bottom of cistern it's actually from the pipe near the toilet as nowhere else is wet 'cept at back of loo on the floor so that will have to be fixed and yes the overflow is incorporated into it. As you say then, the float level may be too high anyway and the loss of water was always going into the loo but now showing up on the floor behind the toilet because of the leak on the pipe! Oh dear, what a curse. Thank you for your help, much appreciated.

[The Builder]

OK, so it's one of these that's leaking then............

http://www.homebase.co.uk/en/homebaseuk/flush-pipe-connector---internal-374379

It sits in the pan and the flushpipe goes into it. Nothing to go wrong usually. One common cause is the pipe going out of line by being knocked for instance.
Getting everything lined up is tricky. The usual fault is the pipe being too short, and not going into the connector squarely at right-angles to the pan.

[dunnitall]

Thanks again for your help Builder, all too complicated for us to sort so will get a friend of 'the extended family' to have a look, it's not leaking too badly and have a container under it so will be ok till tomorrow. Thanks again for your quick and helpful response.