Plumbers? Cistern inlet pipe union leaking after valve change

DorsetDude

DorsetDude

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Keith
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Hi

Inlet valve in the cistern on my close coupled khazi packed up last week. Took it out and trotted off to B&Q where they had the exact same one (fluidmaster) for £12 ish. Great. bought it, took it home and fitted it. Cistern now fills and flushes again.

Unfortunately I have a drip and I think its coming from where the end of the copper pipe connects to the plastic thread on the bottom of the new valve. Undone it and tried to re-tighten it, still dripping but much slower now.

Any tips for doing it properly and stopping the drip? I tried PTFE tape but because the access is so tight and Im cack handed I couldnt get the tape to stay on the male bit of the thread.

Cheers
 
I assume yu have a tap connector with a fibre washer...

1. Has the fibre washer fallen out?

2. My brother never fits the fibre washer. He just uses lots of PTFE tape.

If everything is new, I will use the washer. If not, I use tape.

Remember though, you are not trying to seal the thread, it's the face to face connection which usually has the washer in between which needs to seal. The thread just applies the force to achieve it.


Steve.
 
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Dont recall seeing a washer, unless its still sat in the "female" nut bit which screws upwards onto the bottom of the valve.

The female bit im tightening is like the "E" in the pic onto a bit like "A". So there should be a washer in it? Can I buy a washer anywhere easy, like InExcess or wilkinsons? thanksView attachment 37007
 
Yes. There should be a fibre washer as marked 'I' in your picture. It will either be dark red or light blue (or disintegrated into a million pieces).

If you can't find it, take off all of the PTFE tape you have on there and start again. You need to put it on in the right direction - so that when you screw the brass piece on, it doesn't try to unwind it but it pulls it into place. You need at least ten turns with a few millimetres overlap so it mates with the flat surface of the brass piece where the washer should be.

5570c902-1a53-4d3a-a436-0d1732807a1f.jpg



Steve.
 
Thanks Steve. :thumbs:

Would rather fit a washer if I could as I struggle with the tape stuff. It just goes into "string" rather than staying flat when I try to apply it.
 
Also, sometimes there can be a an "O" ring on the end of the copper pipe fitting inlet (similar use to an olive) It was the case with mine recently. Make sure when you fit the copper section that the pipe is pushed in tight onto the plastic fitting and try and hold up when tightening the nut. Sometime you think you are tight and it may just need that little extra turn.
 
Keith, if you have to go out again to make a purchase, pick up a roll of Loctite 55 thread. In my opinion it's much better than PTFE tape and far more versatile.

I had to replace the motorised valve on my central heating system yesterday and used good old Loctite on all of the threads.:)
 
killwilly said:
Keith, if you have to go out again to make a purchase, pick up a roll of Loctite 55 thread. In my opinion it's much better than PTFE tape and far more versatile.

I had to replace the motorised valve on my central heating system yesterday and used good old Loctite on all of the threads.:)
Click to expand...
Should the need arise, when using that, is it possible to undo the nuts again in the future?
 
DorsetDude said:
Should the need arise, when using that, is it possible to undo the nuts again in the future?
Click to expand...

Yes, no problem. Being a thread and not a tape like PTFE, you wind it on the hollows of the thread making a perfect seal. I used to use Boss White, or similar, but found it a bit messy, plus it would harden over time. Loctite is also perfect for remaking the packing glands on stop taps. I have used PTFE tape for this in the past, but it doesn't last. Turn the tap on and off a couple times and the gland will start to drip.
 
mattyg said:
Plumbers Gold
or
Plumbers Mate

/thread.
Click to expand...


Plumbers Mate is great stuff and brilliant for making a joint between a sink and a waste, but no good for making a seal on compression fittings. These days, where possible, I use push-fit fittings on both cold and central heating, quite a bit more expensive to buy, but worth every penny for the time you save, plus fewer leaks.:)
 
All good replies for sealing threads... but this isn't a thread sealing issue!


Steve.
 
killwilly said:
I believe it was you who recommended PTFE.
Click to expand...

I did - but to replace the missing washer, not to seal the threads. The Loctite or Boss White might work but I would rather have something more solid which I could compress against the two mating surfaces.

Although the bulk of the PTFE goes around the thread, the bit which is doing the sealing is the bit which overlaps the end and takes the place of the fibre washer.


Steve.
 
I think i'll try and source another washer rather than my ham fisted attempts with the tape.
 
Just ask for a 1/2" fibre washer,(they usually come in packs of 10 for a quid) forget loctite, forget ptfe, if they were the option the manufacturer would have included one of them in the packet, I think you may have dropped and lost the washer that would have come with the valve mate,either that or when you have disconnected the tap nut just check that the old washer has'nt gone underneath the nut causing you the grief.
 
mex said:
Just ask for a 1/2" fibre washer,(they usually come in packs of 10 for a quid) forget loctite, forget ptfe, if they were the option the manufacturer would have included one of them in the packet, I think you may have dropped and lost the washer that would have come with the valve mate,either that or when you have disconnected the tap nut just check that the old washer has'nt gone underneath the nut causing you the grief.
Click to expand...
Quite possibly the latter. The only washer that came with the cistern valve was a great big plastic one that fitted on the inside of the cistern between the valve and the cistern base.

Cheers
 
The fibre washer doesnt come with the valve.. it comes with the tap connector, dont use ptfe or locktite or boss white. Just get a fibre washer. You would have been better off getting a ballvalve with a brass thread to ensure you dont crossthread it but never mind.
 
gerry s said:
The fibre washer doesnt come with the valve.. it comes with the tap connector, dont use ptfe or locktite or boss white. Just get a fibre washer. You would have been better off getting a ballvalve with a brass thread to ensure you dont crossthread it but never mind.
Click to expand...
I was thinking that but then i thought, well brass is not known for being a particularly hard metal is it. However my next attempt will be the third unscrew/screw on the plastic fitting, lets hope I havent already cross threaded it.
 
DorsetDude said:
I was thinking that but then i thought, well brass is not known for being a particularly hard metal is it. However my next attempt will be the third unscrew/screw on the plastic fitting, lets hope I havent already cross threaded it.
Click to expand...

Hardness isn't really an issue, because only a moderate amount of force is required to get a seal. If you have to wind the joint up until it squeaks then there is a problem. Hope you've not cross-threaded too, and 3rd time works out for you. :)
 
mex said:
forget ptfe, if they were the option the manufacturer would have included one of them in the packet
Click to expand...

True. But my brother has fitted thousands of them using PTFE instead of the washer and they never leak. It's his preferred method. It's also the only method when you have lost the washer or it has disintegrated into a million pieces and all you have is PTFE tape!


Steve.
 
Right, uncoupled again last night (ooh matron), got my 1/2" fibre washer, it wouldnt fit over the pipe easily, got a screwdriver to it and forced the edges down round/over the pipe. re assembled and only slightly tightened the nut, didnt go mad. Overnight and this morning - no drips. So think thats it. Thanks all!
 
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