Fixing Flush Pipe Leak

[Traveller 47]

I want to replace the seal between the back of the toilet and the lower end of the flush pipe. I assume that I do not need to empty the cistern (modern slim-line low level type) when the flush pipe is removed. Am I correct?
The new seal seems to just be a push fit. Is necessary to put any sealant on the new plastic seal or will it be watertight when just pushed in to the back of the toilet?
Comments appreciated.

 

[Rtplumb]

Here's my advice for what it's worth.

1. Always isolate the water supply to the cistern via the iso valve or if the cistern doesn't have one, turn off the mains supply.

2. Flush the cistern. Make sure it's empty. Accidents happen. You don't want a few litres of water all over the place.

There are a couple of types of flush pipe connecters you can use.

1. There's the cheap plastic type which tend to be a loose fit in most WC's but will do the job until they get old (which doesn't take long, just a few years) and they harden up and fail.

2. There is also a heavy duty rubber connecter (my personal preference) which can be difficult to fit but with the use of a smear of silicon grease (or washing up liquid), they will bed in. These last for decades.

You haven't mentioned the age of your WC. On some older models the modern flush pipe connectors won't fit. So you have to use old school methods to get things sealed up. Anything made this century will be fine. Anything from the 1970's and before , you'll struggle.

Use a reputable stockist to purchase these items.

Oh, and did I tell you to make sure the cistern is empty and the supply of water is off before removing the flush pipe?

Hope this helps.

 

[Traveller 47]

Yes, a great help - thank you. I will try to obtain the heavy duty rubber connector this week.

 

[Rtplumb]

View attachment 257472_wl.webp
Here's a picture of the connecter. They also come in black. Pick one up in Wolseley for a fiver. Code number 257472.

 

[Traveller 47]

Thanks
[automerge]1738005165[/automerge]
Having dismantled the toilet to fix the leak, I have found that the soil pipe/toilet joint has also been leaking. It is a flexible soil pipe and only 3 years since it was fitted professionally. When pushing it back into place is it worth securing it with a zip-lock strap.

I’m dealing with a back-to-wall toilet fitted against a bathroom unit and it is pretty difficult to get at anything.

 

[opplumbinghub]

I want to replace the seal between the back of the toilet and the lower end of the flush pipe. I assume that I do not need to empty the cistern (modern slim-line low level type) when the flush pipe is removed. Am I correct?
The new seal seems to just be a push fit. Is necessary to put any sealant on the new plastic seal or will it be watertight when just pushed in to the back of the toilet?
Comments appreciated.

You don’t need to empty the cistern when changing the seal, though some water might drip from the pipe. The new seal should fit tightly without needing sealant. Just clean the surfaces first, and you can use a little silicone grease to help it slide in. If it leaks later, you can try sealant, but it’s usually not needed.