Check that it isn't the two nylon 'rods' that are sticking and won't allow the push buttons to return to the correct 'closed' position. A liberal amount of siliicon spray made it all work much smoother and no more leakage.
Neil
June 2011
I am having a similar problem, believe the leak is where the pipe from the cistern goes into the toilet ifself, a grey rubber seal..any suggestions. Can I buy a spare seal?
KP
February 2009
You need to replace the flush-valve seal (Also known as dual flush valve washer, or diaphragm washer) at the bottom of the flush assembly.
How to do it :
http://www.lunns.net/cisternspares/roca_flushvalve_installation.pdf
Roca Part # :
8-22403000, about £1.53 + VAT from ROCA, £7.19 from Lunns (70122 - Roca Diaphragm Dual FV Washer)
happy flushing
Dave
dave
November 2007
I suspect this is a Grohedal flushing mechanism and I found I had to get a replacemant part 43 544 which includes the washers ( washers are not available separately ) Look at Grohedal on this web site for others with this problem.
Bill Clark
October 2007
Usually a good plumbers' merchant will keep them in stock. Take the old one with you as a pattern.