New toilet float valve connector leaking at union

[mleggatt]

Our toilet float valve recent broke and didn't stop filling the cistern. I've tried to replace it with a bottom entry fill valve from screwfix:

https://www.screwfix.com/p/fluidmaster-bottom-entry-brass-shank-fill-valve/47792

It fits the cistern but I can't stop the joint connecting the bottom of the valve to the existing copper pipe and brass fitting.

I've tried using a fibre washer in the brass connector (nut at top of photo with yellow arrow) and also a rubber washer and tightened it down but both leak water. I also tried PTFE tape around the thread but that didn't make an difference.

I have considered replacing the brass connector where the washer sits and is compressed by the brass threaded pipe in case this is pitted on worn.

Any hints or tips would be appreciated.

Thanks
Martin

 

[Ian H]

I think you really want this fitting:

https://www.screwfix.com/p/straight-service-valve-15mm-x/58008

 

[foxhole]

Those fittings often need two washer to seal, though all in copper make it hard to get required movement to secure, many use flexi connectors which are easy fix.

 

[terryplumb]

The fitting you have requires PTFE tape to be applied to the brass tail of the float valve. Several turns, wound fairly tightly . looking Down from above wind anti clockwise, ( if you are laying on your back looking up , it would be clockwise ) .That fitting does not need any washer ,the seal is made by sealing the threads .
So undo the lower nut ( the compression joint to supply pipe ). After applying the PTFE tape ,tighten up the top nut ,then re make the bottom compression nut to supply pipe.

 

[mleggatt]

Thank you for everyone's replies. I did try Loctite55 Pipe Sealing Cord on the threads but may not of used sufficient and will try again.

If that doesn't work I'll take a look at the fitting you mentioned "Ian H".

I'll let you know how I get on.

Thanks
Martin

 

[Madrab]

not enough tape, you should see a little up past the end of the female fitting. Buy a roll of gas PFTE tape (thicker). start at least 1/2 way up the tail heading down, overlapping 6 tight wraps going with the run of the thread (clockwise looking end on) on the fill valve tail with the last one very slightly overhanging the bottom end of the thread.

 

[fixitflav]

Thank you for everyone's replies. I did try Loctite55 Pipe Sealing Cord on the threads but may not of used sufficient and will try again.

If that doesn't work I'll take a look at the fitting you mentioned "Ian H".

I'll let you know how I get on.

Thanks
Martin

If it's a modern sink with round holes for the taps, you might need to get somebody to hold the tap from turning while you tighten the fitting.

 

[Madrab]

If it's a modern sink with round holes for the taps, you might need to get somebody to hold the tap from turning while you tighten the fitting.

If it was a sink he was talking about then that would be great advice, unfortunately tho ...... he's talking about a toilet.

 

[fixitflav]

If it was a sink he was talking about then that would be great advice, unfortunately tho ...... he's talking about a toilet.

Good point! But even more so with a toilet fill mechanism. Still needs to stop it rotating while he tightens the fitting. If there are spanner flats somewhere, OK. But often these types of thing won't take much torque, which is why they use a tap connector with fibre washer, not a compression fitting.

 

[mleggatt]

Hi all,

Thanks for replies, learnt a few things. In the end I replaced the copper pipe and various unions with just one flex hose that attached to the thread on the isolator valve and the thread on the bottom of the valve.

Looks a lot neater and sealed first time.

Thanks again
Martin