Leaking toilet tank

[Note3]

We have recently moved into a house needing lots of rennovation and have discovered a leak from the toilet tank. It appears to be the pipes as I've turned the water flow off (on the little valve you turn with a screwdriver) and the dripping seems to have stopped. I've googled some guidance and am going to try and change the seals and things on the tank myself in the hope it cures the leak. We can't afford more tradesmens invoices right now if avoidable plus I can't face having to find and contact yet more companies and sort out access...its neverending.

Hoping it's as straightforward as Google suggests. If anyone has done this and ha any advice I'd like to hear it

If it is actually leaking (not just condensation on the cold cistern) you have to identify where from. Put a little food dye into the cistern and stir it, then watch for that colour coming out. Tie kitchen roll or bog roll where you think the leak might be. It might be near the top where the handle, and possibly the overflow and supply pipe, do in; or it might be at the bottom where the supply pipe connects to the ballcock. Or it might be under the middle of the cistern where there is a large rubber washer underneath when it is fixed to the back of the pan.

Or it might be overfilling because the ballock is dripping. In this case it will stop when you flush it, but the water level will rise above the "water level line" marked in the inside back of the cistern.

Post some photos inside the cistern if you like.

Thanks you've been a great help. I am about to do school run so will pick up dye and then post pictures tonight.

Please excuse the red brick dust over everything in the pictures. We've just had house rewired and despite a clear up the dust is literally everywhere still!

The final picture shows the water damage as we noticed the wallpaper was coming away (that's what first got out attention). I peeled it off and the patchy bit in the bottom corner is where it was soaked. Was amazed as figured the water would just be affected by gravity and only gather in kitchen ceiling below but it's done that as well as gone up the wall...grr!!

My detective work with the dye has not gone far. I put a load in the cistern and turned water on but no dye had appeared in the leaking water. I have tried it all and followed up the pipe and it's defi8leaking at the top of that bendy tube where the water comes in (the nut at very top is wet)

*dried it all not tried it all

the bendy tube may be the problem. It is scrunched up very tight, which can cause them to crack and burst (there is a flexible plastic hose inside the steel braid).

The nut at the top is screwed onto the plastic stem of the filling valve. It's not unusual for the plastic to get damaged if the metal nut goes on cross-threaded, as may happen if the flexible hose is under stress like yours. I don't know if you can get an extra-short hose. If not, I see there's an extra valve just under the flexible hose. You don't need that as well as the one incorporated in the hose fitting. Removing that (turn off the water supply first) would give you an extra couple of inches for a hose.

I'd suggest a new flexible hose, as short as you can get, and preferably also a new filling valve. Fluidmaster make one with a brass shank, to reduce the risk of damage by cross-threading. Screw the hose onto the valve before you fit the other end to the copper pipe to improve your chances of getting it straight.

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

Quality of the hoses is very variable and this is the only branded one I can find
www.screwfix.com/p/fluidmaster-flexible-hose-connector-300mm-with-isolating-valve-15mm-x-x-300mm/1622g

Thanks get my much for your help. I had a development overnight as discovered blue water in pot under the flexible hose so definitely seems to be that bit leaking. Pleased to see the blue dye test worked as I almost feel like I know what I'm doing now haha

Going to check those links tonight thanks and plan the great changeover when crazy toddler asleep