Leaking water from a small hole in the back of the toilet bowl.

That is, there is a problem with the plug of the drain outlet of the water tank, and it should be ...... that the flush port cannot be re-blocked by its own weight >>>More

Toilets can be cleaned in several ways:

1. Vinegar descaling. >>>More

The key is that the rubber pad (may be an engineering plastic cushion) at the water inlet can not suppress the water flow of the inlet, and a rubber pad of the same size as the water inlet can be cut and glued to the original rubber pad (may be an engineering plastic cushion) with universal tape, so as to increase the pressure of pressing the water flow of the inlet water, and the float ball will reach a certain height with the water level, and the rubber pad (may be an engineering plastic cushion) will be added by the lever to easily block the water flow of the inlet water. There is also a step to tighten the cushion by turning the screws behind the engineering plastic cushion to adjust the tightness of the cushion in a clockwise direction a few times to tighten the cushion. In this way, the problem of water leakage is solved.

Your drain valve is not sealed.

Turn the drain valve counterclockwise, and when you hear a "stuck" sound, you can remove it. Wash thoroughly with the hose of the nozzle. Wash the yellow water in the water parts. >>>More

You didn't get that picture right. Put the blue one (pontoon) through the square column. The short crossbar under another vertical pole attached to the pontoon is upward. >>>More