Step 1: Tighten the grub screw

Remove the lid from the toilet cistern.
Find the small screw that holds the plastic arm of the flush to the metal handle. This is the grub screw. It should be tightened to hold the arm firmly in place.

Tip: Once every six months tighten the grub screw to prevent further trouble with your flush.

Step 2: Check the linkage

The linkage is the metal hook that connects the handle to the pump mechanism. Check to see if it's bent or twisted. If it is, it could snap with use, so it needs to be replaced. To change it, pull up the plastic arm below the linkage and work the linkage out of place. Make sure you hold on to the plastic arm, or it will disappear into cistern and be lost forever! You'll then need to replace the whole pump, which is a much bigger job! Work the new linkage into place.