Hello, I am having a problem with a running toilet (Caroma Concorde 6-3). It is making a hissing noise pretty much all day long. I have spent a couple of hours googling but have not been able to find any videos of the same cistern. The noise is coming from the blue arm (see photo). I emptied the cistern, and when it refilled, the arm engaged, but I think when the water level is dropping, the arm is disengaging and causing the noise. I'd like to buy some replacement parts but don't know how to remove the parts first. Can anyone help?![IMG_E4176[1].JPG IMG_E4176[1].JPG](https://us.v-cdn.net/6038643/uploads/migrated-attachments/ba446fba572c68004f2dbc6144f26e49.jpg)