Fluidmaster brass shank too long

[RobMax]

I am replacing an ancient ball cock and valve with a Fluidmaster Pro. The brass threaded shank of a Fluidmaster Pro is too long for the existing height of the supply pipe. It is a bottom fill.

I am minded to cut the brass shank and wondered whether this is the best option and if so what tools would best be used.

 

[Burnerman]

It is possible, but only recommended if you can cut the brass thread absolutely flat and square or you'll be plagued with leaks afterwards.....
much better to alter the pipe work leading to it if you can.
If you do cut, use a tap connector with a new fibre washer, and file a 'lead' onto the brass thread so the connector will couple perfectly.
The brass thread will need to be exactly the correct length, and the rubber washer inside will only compress to a certain degree - so your cutting will need to be spot on.
John

 

[RobMax]

Thanks John, if I went with the cut do you have any suggestions regarding a good tool to use?

 

[Burnerman]

The obvious tool of choice would be a fine toothed blade in a hacksaw frame (not the junior type - the blade is too thin and wanders everywhere) followed by a flat second cut file.
Alternatives would be an angle grinder with a 1mm slitting wheel - it depends what you have.
Other brands of fill valve (Delchem, Torbeck) have a threaded part a little shorter than the Fluidmaster, but they aren't brass!
John

 

[RobMax]

John, thank you for your guidance - much appreciated.
Rob

 

[PippaM]

I found these posts as I had exactly the same issue and was looking for some advice!! If it had been in my own home, I would also have considered adjusting the supply pipe. However, I was doing a favour for our local Community owned swimming pool - so really, really didn't want to start altering the existing pipework!
After a lot of thinking, I decided that the problem was the gap between the top of the black sealing washer and the bottom of the fill mechanism. The washer needed to be snug against the bottom of the fill stem AND fit into the hole in the bottom of the cistern. This wasn't happening as the brass shank was too long and when fitted into the inline valve below the cistern, the bottom of the fill mechanism stem was about half a centimeter off the bottom of the cistern. (I measured the gap very roughly by pushing things like a pencil & allen keys (!) into the gap to try and gauge it!)
So, I took the black washer off...and put on 5 or 6 large white plastic washers, then the black washer on top of these. In effect, this made the fill stem push on the washer. I put it in - without much real hope - but, blimey, it worked!! I only had to do the bottom nut up hand tight - and nary a leak was seen.
I am rather pleased with myself - and thought I'd share!

 

[HERTS P&D]

And when it leaks, who do you think they will blame for bodging up the plumbing. This will come back to bite you.

Andy

 

[PippaM]

Thats OK, there are options.
Also, I wonder if other DIYers will come across this issue. If you have to replace the fill valve and you buy a replacement one, you might expect (as I did) that it would do just that - i.e. replace the existing one! As noted in the posts above, this may not be the case. The shank length on the bottom fill ones do apparently come in different lengths and may vary from your original.
This is what happened to me and once I realised what was going on, I had a few options.
a) go and swap the Fluidmaster for another brand that had exactly the same shank length as the original. (If possible!)
b) alter the supply pipework. (Some DIYers may not fancy this one! I didn't...)
Or, you have to alter the one you've bought. There seems to be two criteria (as far as I can see) to make the fill valve fit properly and not leak. The sealing washer needs to fit snugly into the hole in the bottom of the cistern and the shank needs to fit accurately into the supply pipe. As was suggested in the previous posts, you can cut the shank to length...but - as noted - this needs to be done really accurately. I (and maybe other DIYers) didn't feel confident about this.
My option, of adding a Spacer - created from washers (in effect) ABOVE the sealing washer allows this washer to now seal the hole tightly and it effectively makes the shank shorter, so that fits accurately into the supply pipe. In fact, I have now used this method on a second toilet - which also had a failed fill valve. I simply offer it as a possibility - in the spirit of DIYness.
Pippa

 

[scoobydo123]

I install using flexi's. Very handy if the toilet needs to be pulled out for unblocking purposes etc. Just buy a longish one and install in a looped fashion

 

[Steelmasons]

I install using flexi's. Very handy if the toilet needs to be pulled out for unblocking purposes etc. Just buy a longish one and install in a looped fashion

Plumbing @ it's best scooby , although supply will have to be cut in order to fit flexi.