Sometime ago, I envisaged to fix a leakage in the toilet flush tank. After replacing the ‘K’ washer, the leakage however persisted. Click here for the post. This weekend I examined the outlet valve and the flush pipe conditions, especially how the outlet valve seats on the flush pipe. I could not find any apparent problem just by looking at them. So I removed the flush pipe and examined the washers. I discovered that the wedge washer inside the flush tank has worn out and was rather brittle while the seating washer outside the flush tank was still good.
Today I bought a new wedge washer from the Bunnings warehouse. Bunnings did not actually have the exactly same washer but the Bunnings staff suggested a different shape that would still work. The washer was quite cheap, only about $2. Later I installed the new wedge washer. The leakage virtually stopped although I noticed there was still a tiny amount of water leaking out of the flush tank. But the leaking might be due to the outlet valve not seating firmly on the flush pipe (It was quite wobbly). Overall I am happy with the way it turns out.