Pop-up waste issue

[WitchetyWoman]

I've got a sink on top of a solid wood vanity unit (gap removed and internal 3 sided 'box' created to accommodate the waste and make it still usable as a working drawer.

It's got a solid brass pop-up waste. Sometimes the popping up or down of it gets stiff and I have to lube it where the two metal cylinders slide against each other, then it's fine aga for months.

Today I popped it to come up and it came up way higher than normal, wouldn't go back in and be seated properly, and for the first time ever a. The two parts were totally separated from each other and b. The spring was able to be taken out (have never even seen the spring before).

I tried to push it down and start turning it to reattach it but couldn't seem to do it.

I thought temporarily do I can wash my face, I'll just pop the top piece in - I tested it and could get it out but then it dropped about 3mm below the level of the circular brass ring the surrounds the plughole - and I can't get it out now!

Questions:
Will I have to undo the plastic u-bend piece so I can push the top pop-up piece back up (am I stuffed if the plumber sealed the joints when he plumbed in the sink)?
Do I just need to use more brute force to press down on the top piece (with the spring reinserted) - is that why I couldn't do it before, I was being too gentle?

I do t think force is the way. When you say, ‘pop up’ do you mean you just press it? There’s no lever attached somewhere?

Yes, you push it down to close it, and do the same to get it to come back up. I'll have a crack at it later 🤞..

It's called a clacker or click-clack waste. The mushroom screws out and there is a brass looking spring unit that can be unscrewed and replaced with new. Measure your old one carefully, the lengths seem to vary a bit. There are also rubber sealing rings that can be replaced with new. I prefer to get Bristan but there are at least two different mechanisms though they look the same from above. You can get a handful of the replacement spring units at modest cost once you have found one that fits. You should be able to keep your existing mushroom, though if you can match the brand or fit, you could buy a complete new set for convenience. Chrome plated brass are the most popular and durable.

You can grease the threads witha tiny smear of white silicon plumbers grease to reduce the risk of seizing.

"Pop-up" are the sort that has a knob or rod to push the mushroom up from underneath. They leak.

(If you can't lift the mushroom out with your fingernails, dry it and use blu-tak. But I recommend getting an unsightly rubber universal plug until you can replace the spring)

This

Yes, press to push down, press again to get it to pop up.

I undid the u pipe and was able to push the 'lid' (I'm calling it lid, the bit that closes the plughole and keeps the water in) up to where I could grab it. Watched a couple of YouTube vids. Fiddled around, took the two parts of the brass mechanism and lubed them up with treadmill lubricant, Popped the lid on and found that locks it into place with an anticlockwise turn. Cross everything but it seems totally OK now 🤞🙂. And yes, I went with a normal (brass) plug in the bath!

Brilliant. Hopefully it stays done. I like the sound of Piglet John’s blutack idea!
DM has fancy things in her bathroom and somethings always going wrong. Mine is quite basic and quite reliable as long as I don’t drop things in there.