Weeping Joints

[garrymum]

Further to my post yesterday about a leaking toilet, I have removed the cistern, replaced the doughnut washer, tightened the cistern nut and replaced. I also renewed the isolating valve as that was leaking when the screw was turned.

It is now weeping from a couple of joints I think. The plastic inlet into the cistern. Seems to to weeping and coming down the plastic thread from the float valve. I have tightened the plastic nut as much as I can and it still weeps ever so slightly. I also think it may be weeping from the upper compression joint nut on the new isolating valve. I have tightened all nuts as much as I can / dare.

What is the best method of stopping weeping compression joints?

 

[chr15]

Undo the relevant capnut from the weeping joint, pack it with jet blue jointing compound, tighten cap nut, hey presto, no leak!

 

[Goldspoon]

You can also wrap ptfe tape around the thread and, on the iso valve, around the olive. Iso valves can be tightened nice and hard (grip the body of the vave with a second spanner or grip to prevent it all spinning). The plastic thread should only require hand tight plus a little bit extra (the aforementioned washer providing the seal.

Does the one on the plastic thread have a flat washer in?

 

[garrymum]

Does the one on the plastic thread have a flat washer in?

Yes, I put a washer in the lock nut that connects to the plastic float pipe thread. I think it's leaking above this joint, where the big plastic nut secures the float valve to the cistern.

I may remove the float valve completely and re-fit, maybe the washer in the cistern is not totally flat with the base of the cistern.



Chr15, thanks for the tip on Jet Blue Jointing compound.

 

[chr15]

I may remove the float valve completely and re-fit, maybe the washer in the cistern is not totally flat with the base of the cistern.

If you do remove the float valve, check for imperfections on the porcelain where the rubber washer makes the seal on the inside of the cistern. If there are any raised spots or blobs you should remove these (carefully) with something like a sharp flat bladed screwdriver as these imperfections would be enough to make your cistern leak, have seen it before.

Also, check the condition of the black sealing washer, the best ones IMO are the conical ones, they bite into the edges and give a better seal.

 

[garrymum]

Also, check the condition of the black sealing washer, the best ones IMO are the conical ones, they bite into the edges and give a better seal.

Thanks. Where would I get the conical washers from?

 

[chr15]

Well they are usually supplied with the float valves but some are better quality than others, again you could try plumb center or b & q might stock them.

 

[powell30]

Not so sure it's your washer thats faulty, just the reinstall. If you had a seal before i can't see why it shouldn't seal now and that points to your workmanship...no offence intended. Are you sure it's leaking from the cistern end and not the plastic threaded nut that your tap connector fits onto? These can and do split (brass to plastic not a good mix). If so it's a replacement float valve. Secondly, did you install the float with the key edge leading (a shallow rirdge that if screwed on the right way ensures the float centres on the hole and means your less likely to have leaks. Finally, if all else fails try silicon, plumber mate or even a secnd rubber washer below the cistern

 

[Kes]

You can also wrap ptfe tape around the thread

Wrapping anything around the thread on a compression or flange joint (such as a tap connector) is counterproductive. The water will be escaping either from the contact point of the olive and the fitting body or pipe, or from the contact point of the flange and the tap/ball valve etc. The thread does not make the seal.

By all means (and I think you should) use ptfe tape around the olive or, if you can, around the flange, and then use the nut/thread as it was intended, to tighten the joint.

 

[garrymum]

Not so sure it's your washer thats faulty, just the reinstall. If you had a seal before i can't see why it shouldn't seal now and that points to your workmanship...no offence intended. Are you sure it's leaking from the cistern end and not the plastic threaded nut that your tap connector fits onto? These can and do split (brass to plastic not a good mix). If so it's a replacement float valve. Secondly, did you install the float with the key edge leading (a shallow rirdge that if screwed on the right way ensures the float centres on the hole and means your less likely to have leaks. Finally, if all else fails try silicon, plumber mate or even a secnd rubber washer below the cistern

Thats just it. I have not touched the float valve. Removed the cistern to tighten the syphon nut and replace the doughnut washer. Once cistern back on it was leaking from the float. I must have disturbed it when tightening up the other components. Anyway, took everything to bits, unscrewed all joints and wrapped with ptfe tape. Removed the float valve and checked the washer and replaced everything. Fingers crossed but it seems ok now.