So you have done the smart thing and have been using a toner refill kit to keep your printer or copier running full steam. Toner refill kits are a great way to save money and protect the environment, but don't fall into this trap. Too many people end up with major copier malfunctions because of toner leaks. This happens in many instances because the toner cartridges were not replaced for a long time. Even if you use toner refills, you still need to buy a new cartridge every once in a while.
Most toner refill makers recommend no more than three consecutive refills with the same toner cartridge. Using the same cartridge beyond the manufacturer's recommendation could mean nullifying any warranty that you have. The wear on a cartridge when using toner refills builds up and can lead to cracks or leaks in the plastic casing. Don't let this happen to you. Keep an extra cartridge handy and follow the manufacturer's instructions for how many uses before changing.