Toilet Cistern Upgrade

[gromit]

Hi

Had problems with 11 year old toilet cistern such as inconsistent flushing and bal valve refusing to shut off etc.

Have completely replaced all parts with FluidMaster flapper valve and FluidMaster bottom entry float valve. All working perfectly. EXCEPT the isolating valve has a swivel union joint and fibre washer, but it refuses to mate correctly with the threaded plastic entry of the float valve. On tighteing hand tight with a quarter turn of the spanner, there is still a noticeable trickle of water from the union. The fibre washer seems to be an odd size as I bought replacements but they have a smaller central hole so don't fit.

I have been told to try string and vaseline on another DIY site - is this wise?

I thought all 15mm (half inch) fittings would be standard?

Confused, Any ideas?

Thanks

 

[seco services]

Can't see why your getting a problem but can be a few reasons.
Give us a pic of your iso valve.

 

[DeltaT2]

Hi

Had problems with 11 year old toilet cistern such as inconsistent flushing and bal valve refusing to shut off etc.

Have completely replaced all parts with FluidMaster flapper valve and FluidMaster bottom entry float valve. All working perfectly. EXCEPT the isolating valve has a swivel union joint and fibre washer, but it refuses to mate correctly with the threaded plastic entry of the float valve. On tighteing hand tight with a quarter turn of the spanner, there is still a noticeable trickle of water from the union. The fibre washer seems to be an odd size as I bought replacements but they have a smaller central hole so don't fit.

I have been told to try string and vaseline on another DIY site - is this wise?

I thought all 15mm (half inch) fittings would be standard?

Confused, Any ideas?

Thanks

If it was a plastic tail on the float valve, are you sure you've not cross-threaded the plastic tail? Very easy to do, even an auld hand like me can still do it!!

 

[Charnwood]

A bit late now, but the Fluidmaster PRO45B has a brass shank, although there should not be a problem marrying up the brass nut to a plastic thread. It happens hundreds of times per day.

 

[TicklyT]

Traditional 1/2" tap connectors use a different size washer to 1/2" flexible tails, which many 'spare washers for tap connectors' are designed to fit. Flexis have a restricted bore, so they can accommodate a washer with a smaller hole in the middle.

Ditto the problems with cross-threading the nut on a plastic tail. Check the mating faces line up correctly before starting the nut on the thread - trying to use the nut to pull everything into alignment is an almost certain recipe for disaster with a plastic tail. Once the nut has crossed up, it is very difficult, if not impossible, to get it to run straight on the thread again.

In the past I have got out of trouble by wrapping PTFE tape around a second-hand fibre washer as a temporary fix.

 

[DeltaT2]

A bit late now, but the Fluidmaster PRO45B has a brass shank, although there should not be a problem marrying up the brass nut to a plastic thread. It happens hundreds of times per day.

Granted Charnwood, the Fluidmaster range generally have quite a good plastic thread on them. If it is a cross-thread problem on a plastic thread??
You can square cut about 5mm from the tail of the ½" thread & that should give you a chance to start again, providing of course there's enough play on the pipe to re-connect everything?
HTH

 

[sooey]

Easier to use a thread file to straighten it back up. Not that I ever need one of course.

 

[ChrisOxford]

Check the mating faces line up correctly before starting the nut on the thread - trying to use the nut to pull everything into alignment is an almost certain recipe for disaster with a plastic tail.

Excellent advice, TT. You should be able to spin the nut to the point where there's no discernable wobbliness on the feed pipe using just your fingers. A slight tweak with a spanner and it should be watertight. A smear of LS-X on the tail pipe's end never does any harm either.

You can square cut about 5mm from the tail of the ½" thread...

...and file the end damn smooth so that the fibre washer can seal properly.

You can use the nut that holds it to the cistern as a guide to getting the new end absolutely square. Or so they tell me

 

[gromit]

Hi

Sorted!

Thanks to all who replied especially DeltaT2 and TicklyT!
I cut a few mm off the end, filed it smooth and invested in a new fibre washer - dry as a bone!

I'll make sure I watch out for the cross-threading next time!

Thanks again.