On Sat, 03 Jan 2009 17:50:50 +0000, Alang
wrote:

On Sat, 03 Jan 2009 13:01:58 +0000, MM wrote:

On Sat, 03 Jan 2009 12:54:28 +0000, MM wrote:

Anyway, I just had a brainwave (in the last couple of hours). I
swapped the top part from the downstairs loo with the bathroom one. No
dribbling!!! I've switched the water back on again and flushed a
couple of times. Still no dribbling!!! So it is definitely the rubber
seal on the end of the plunger thingy.

PS to my last post: The seal on the top part from the downstairs loo
has some blue gunk on the contact surface, which I left in place.
Anyone know what this blue gunk is? It must have been smeared on when
the unit was being assembled when the house was built in 2004.
Whatever it is, it has mostly stayed in place despite numerous
flushings over four years. NB: This gunk is definitely man-made, i.e.
not some chemical reaction. It definitely looks as if the plumber
smeared some "stuff" on the seal before assembling the syphon inside
the cistern.

Hylomar blue?

Yes, that must be the stuff, thanks! It must be a most amazing
product, since the product information says:

Non hardening and non setting
Unlimited assembly time
Vibration resistant
Allows metal to metal contact
Resistant to combustion products, water, engine coolant, petroleum,
lubricating oils, kerosene and fluorocarbon refrigerants
Seals surface imperfections
Withstands rapid variations in temperature
Flame, dust and moisture proofing properties

I'll monitor for any dribbling and if it appears again I'll get a tube
of this material. Only £2.95 plus VAT, so it's not expensive.

I think I am getting closer to a dribble-free existence again! Thanks
to all in this thread.

MM