Dual flush button sticking

[Paul O'Flynn]

I have had this problem awhile now and tried wd40 and seemed to work for a bit.
When you flush the big button on the dual flush It sometimes stays down so water trickles in all the time until you give it another tap and it comes back to the top positon.
How can I stop it doing this or do I need to change the whole flush system.
Thanks

 

[SimonG]

Get some silicone grease on all the moving parts on the drop valve and in the push button.

 

[WHPES]

If it's the cable type, check the cable isn't kinked where it goes into the flush valve.

If you can't sort it, replace with the cable -less type.