Being able to fix a ball valve can be a useful skill to have. This will ensure that you can rectify any 

defect which arises that might cause it to leak. By following a few easy steps, you will find that 

you are able to undertake the task without the assistance of a professional.

To begin the process of fixing a leaky ball valve, ensure that the first step you take is to turn off 

the water supply to the toilet. At this stage, you can remove the lid of the cistern and set it 

aside to allow you to empty the water within the tank. This step is required to give you better 

access to the components that you need to repair.

After lifting the cistern lid out of place, carefully lay it flat where it cannot fall over or be stepped 

on. Empty the water remaining in the cistern or bail it out with a jug. Use a rag or sponge to soak

up any large traces of water.

Once the cistern lid has been removed and the water is cleared, you will be in a position to 

examine the components of the ball valve within the tank to determine the cause of the leak. 

No matter what defect is causing the problem, it is likely to be more prudent to install a 

replacement rather than attempt repair. All the relevant components will be available within a kit 

that can be obtained from hardware stores and plumbing supply stores.

Disassemble the mechanism for the existing valve by initially removing the angled pin that holds 

up the float arm, this should be done by straightening the arm and removing any fasteners before

sliding it out of place. You will then be in a position to unscrew the end cap which will allow you 

to remove the piston which controls the float arm. With the components always being  

suspended in water, you may find that the fasteners prove stiff enough to require a touch of 

lubricating oil to help remove it. After loosening the cap, the piston and end washer that makes 

up the ball valve can then be slid out of place.     

Make use of the instructions that come with the new ball valve kit as well as your knowledge of 

the original assembly. This will be required to help you assemble the new components. Reverse 

the work you have previously undertaken by slipping the washer and piston into place first. 

Before screwing the end cap back into place, rub a small amount of petroleum jelly onto the 

thread to ensure that you do not have a problem if it has to be removed in the future. Tightly 

screw the cap back into place before reattaching the pin to support the float arm.    

Once the assembly is complete, turn on the water supply and watch the cistern refill to make 

sure that the leak has been repaired.