Thanks for the reply. There seems to be loss of brake fluid although I cannot locate any leaks in the breaking system. I have replaced both cylinders with new ones and after consulting a local mechanic he told me to check the shuttle valve which I disassembled, cleaned and reassembled. After removing all the air from the system the brakes worked well but only for a day. After that they went to their previous condition where the pedals go full down to actually work a little. I’ve searched the net for another shuttle valve as the mechanic and the manual suggests to replace if it is broken but can’t find any as these parts are hard to find.