Leaking cistern inlet

danrv

Hi
The above join into the loo cistern has started to drip and have tried to stop it but no luck.
The join is a 15mm copper pipe compression fitting to plastic thread on the refill valve.
There’s a fibre washer against the olive which I’ll replace but was just wondering if this is a standard join.
Any help appreciated.

blackshirtuk

Ideally you would have a tap connector between the 15mm and the cistern connection.

Pipe is 15mm and cistern connection is 1/2"



https://plumbingsuppliesdirect.co.uk/compression-female-iron-elbow-multiple-sizes-each-15mm-22mm-28mm-copy/

Be careful not to tighten too much as the cistern connection will split if you use too much force

Tom99

As above or try some PTFE tape round the end of the copper bit incl the fibre washer, or if you can find a rubber 'O' ring washer that might work.

danrv

Thanks for the replies.
Have tried PTFE tape, didn’t do a lot.
I have quite a few fibre and rubber washers but they’re not stopping the drip. Maybe the washer
that’s on there is a particular size or thickness and the same is needed.
Strange that it’s been fine since I moved in last May.

Also not a lot of room between the cistern and the wall for an adapter. Maybe a right angled one if available.
Note taken regarding tightening on the plastic thread.

Rodders53

That is a right-angled tap connector. No obvious need to change it from that picture.

The fibre washer needs to be wet to soften and seal up. Some put a smear of plumbers mate or similar compound (boss white etc.,.) around washer to aid sealing. Looks to be some evidence of that on the copper to me?

Plastic thread damaged? Easy to over tighten brass nut. PTFE tape around the thread only may help if it's letting by that way.

New ball-valve assembly may be needed if too damaged?

danrv

Thanks for the reply.
I was referring more to a right angled adapter from 15mm to 1/2” rather than a connector.
Water sprays out from the nylon locking nut so thought they maybe a hairline crack in the thread.
Have taken out the ball valve assembly and inspected it but can’t see a problem there. I can always replace it anyway.

EachPenny

danrv wrote: »

Thanks for the reply.
I was referring more to a right angled adapter from 15mm to 1/2” rather than a connector.
Water sprays out from the nylon locking nut so thought they maybe a hairline crack in the thread.
Have taken out the ball valve assembly and inspected it but can’t see a problem there. I can always replace it anyway.

Sounds like it is possibly a problem where the white plastic threaded connector is fitted to the valve body. If there is a leak there then the water could be squirted back through the hole in the cistern.

The wall of the cistern looks quite thick, and there is no sign (in the photo) of a nut on the inside of the cistern. Has this (and a sealing washer) been omitted because the length of the valve was too short for that thickness of cistern wall?

If there is no nut on the inside then tightening the one on the outside might be straining the connection into the valve body.

A picture taken about two inches to the right of the one you've posted would be helpful.

Jonesya

I'd try a good smear of LS-X leak sealer around the olive and washer.

It's quite useful stuff.

Mr.Generous

The connection doesn't look like a tap connector to me, it looks like a compression coupling with an olive. If it is you're not going to be able to tighten up enough against a plastic thread to make a seal. You can get brass threaded valves which would work, to try and get a seal on that in an 'emergency' I'd PTFE tape the thread, then tape the olive in place with about 10 wraps and try and get a compression seal against the tape which would not require anywhere near as much tension against the plastic thread. With weeps like this its easy to spend far too much time trying to fix a bad job than just fitting better parts, a metal thread inlet valve would be my first thoughts, It looks like an old side entry cistern or water tank.

danrv

Pic showing nut on inside of cistern.
Can’t understand how the leak has got so bad. I can only turn water on when I need it.
The ball valve is working fine as it shuts of the water on refill.

danrv

Mr.Generous wrote: »

The connection doesn't look like a tap connector to me, it looks like a compression coupling with an olive. If it is you're not going to be able to tighten up enough against a plastic thread to make a seal. You can get brass threaded valves which would work, to try and get a seal on that in an 'emergency' I'd PTFE tape the thread, then tape the olive in place with about 10 wraps and try and get a compression seal against the tape which would not require anywhere near as much tension against the plastic thread. With weeps like this its easy to spend far too much time trying to fix a bad job than just fitting better parts, a metal thread inlet valve would be my first thoughts, It looks like an old side entry cistern or water tank.

Thanks, will try that.
Yes, I notice replacement inlet valves have brass threads.
Maybe I’ll take the assembly along to the local plumbing store.