Cistern inlet pipe repair

macwal

Looking for a little advice on how to repair this...

The inlet pipe to one of the toilet cisterns started leaking over the weekend (isolated for now).

The supply pipe is 15mm diameter beige plastic (67291 spec). Attached to the pipe is a compression fitting (nut + olive) and the other side of the compression fitting is a nut, which is then directly connected onto the cistern inlet/float plastic threaded bit which goes through the bottom of the cistern and into the cistern.

There are no flexible pipes/fittings between the inlet pipe and the cistern inlet/float device inside the cistern.

The leak is occuring at the connection between the compression fitting nut (not the nut/olive combo that is fitted to the supply pipe) and the plastic threaded part of the cistern inlet/float. It doesn't look like it was put on properly/squarely, and there is silicone on the threaded portion of the cistern inlet/float.

So I'm wondering how a pro or seasoned DIYer would tackle this? I'm thinking of cutting back the inlet pipe a bit, as it also bends slightly around the bowl outlet sewer pipe (adding stress/pressure to the connection), and fitting some type of flexible pipe between the supply pipe and cistern inlet. Does this sound ok, anything else I need to consider?

Would people put a shut-off valve in-line too? Any real need? And if yes, is it possible to get a flexible pipe with a shut-off included?

Also, I'm thinking the silicone that was put on the connection initially was a short-cut/bodged job. But are there any compounds I should be thinking of putting on the connection between the flexible pipe and the cistern inlet (or would plumbers tape suffice here?).

Water supply for the cistern is coming from the tank in the attic.

I know a picture would help, but its in a difficult place to photo properly. Below, I've described the order of parts on the problem area, from the water supply, to inside the cistern.

(Supply pipe)<->(compression nut+olive - nut)<->(plastic threaded part of cistern inlet - cistern)

corkgsxr

http://homebase.scene7.com/is/image/homebase/827467_R_Z001?$LISTER$&wid=110&hei=110 they crossthreaded it.

cut back a few mm and fit a female fitting. A bend or straight type depending on what suits. And go nut and olive side onto the new fitting

macwal

By bend or straight type, do you mean something like this?

ebay.co.uk/itm/Flexible-Tap-Connector-Isolation-Valve-15mm-x-1-2-Female-Compression-Fitting-/160946428088?pt=UK_DIY_Materials_Plumbing_MJ&hash=item25792798b8#ht_869wt_685

Also, are the 15mm and 1/2" sizes usually the sizes that are used in these situations? They seem a bit on the small side, as I measured the nuts (which were 24mm), and the plastic thread on the inlet to the cistern is 20mm (outside diameter).

Seems a lot smaller than 15mm and 1/2" (12.5mm). Trying to avoid getting stuff I'll have to bring back.

macwal

Just to revisit this, finally got around to doing this, but having a problem...

I got a bit of flexible line with a shut-off valve, and have it connected to the supply ok.

The other female end that connects to the cistern inlet valve, it came with a red fibre washer, but I can't get it to seal with the plastic cistern inlet valve. I did have to cut back the end a bit, as as you guessed, it had been cross-threaded, but I have it back to a good bit of thread, and it is squarely sanded and finished, but still leaks, even with some PTFE tape on the thread.

What should I do next? Would a rubber washer work here? Or is there something else that can be put on the threads to seal it up?

corkgsxr

If you cut then its never flat. Give up.

get a female half inch straight. Use some ptfe and thread it on. Then connect the flexy to that