u/Profdizz

I have a problem with the pneumatic flush mechanism on my c. 25y/o Grohe Adagio cistern. It had started responding unreliably to the push button, needing several tries. We've now replaced the button, hose, nipple, bellows and flush valve (photo here is before) -- changed all flushing parts. It now flushes, but often only on the 2nd press, especially after leaving it for some time. To the naked eye, the unsuccessful first press pushes the flush valve laterally, not down, although I can't rule out that the first press doesn't produce enough air/force. Has anyone seen this kind of problem before?