Turn water off at the control alongside the toilet bowl. Flush toilet to completely empty. Remove ball cock arm and note how you took it off (so you replace it exactly the same when replacing.) The whole of the dual flush housing will usually unclip from the toilet cistern. Be careful, force may crack something .Lift out the complete dual flush control. Replace the large rubber flange washer attached to the bottom. Make sure you use the correct washer. I suggest you take it to the hardware store and they will supply the exact replica/ or a kit. Be careful not to put washer in upside down. When done replace the dual control exactly as you found it. Press the entire fitting down firmly over the water drain hole in the cistern. Don't touch the tower shaped inlet valve at this stage. Carefully re-install the ball cock arm exactly as you found it. When secure turn on the water control flow at the tap alongside the cistern. Introduce the flow very slowly to start with otherwise you will have a fountain effect.The cistern will fill gradually. Also introduce a more steady flow of water until the level pushes the ball cock upwards. When full the ball will have the effect of pushing down the new rubber washer at the bottom firm onto the water exit hole at the bottom of the cistern. Usually the ball arm has an adjustment screw on it near the inflow tower. You can use this adjustment to control the amount of water required in the cistern. The idea of the dual flow is to conserve water and normally would not need adjustment once the cistern is full. I suggest you try flushing both levels in turn and check to see if water is still running down the back of the toilet bowl. If the water is running very minimal amounts allow a couple of days for the new washer to seat itself. Tops of cisterns usually clip on by themselves with only minimal pressure. If you have the unsightly drip lines in the toilet bowl, mix up a paste of bicarbonate of soda, apply to the stain and leave over night. You may have to do this several times. It is usually a very cost effective cleaner. Some cisterns have a washer at the top of the water inlet tower, this can be replaced at the same time as the other one. Depending on where you live...different quality of water can cause problems with calcification or other mineral build-ups. I suggest that you also clean the edges of water exit hole which is to be covered by the new washer. It only takes a slight build-up in the area to prevent the effective re-seal with the new washer.
Sykes from Oz, March 2010
