My Caroma Tazman 270 1.6L dual flush toilet has been going strong for over 22 years, quite astounding when you think about our throw-away society. Made in Australia, it was well rated when I bought it. As I recall at the time the City of Toronto had a $150 rebate on for dual flush toilet replacements, so I replaced two. The instructions that came with the toilet date back to 2002 Aug 15.
This toilet is a two piece design, with the bottom being vitreous china and the top being plastic. The plastic top does not sweat and drip water. The dual flush mechanism saves water as we normally use the smaller flush. While the plastic buttons on top have fingernail scratches, the mechanism still works very well.
Recently it has been leaking water, so the outlet valve gasket, what we call the flapper here in North America, needed replacing. I was given the replacement part number 405006 for $6CAD. It seems the gasket is simply peeled off and replaced with the new one. video-1, video-2. I had some troubles ensuring the gasket is flat, and it was then leaking water. I did use the butter knife trick.
Removal of the outlet valve was pretty easy but because the mechanism is plastic I took extra care. The two front tabs need to be slightly bent so that the mechanism can be slid up. The back tabs will follow. Removal and replacement was very simple. video