my sostenuto pedal is not working properly... When I press it down, the felt gets down so the hammers doesn't hit the string directly but when I release it the felt doesn't rise back completely so the hammers, mainly the lowers, gets stucked with the felt and some keys doesn't sound. I've tried to adjust the entire felt to the sides of the piano but it keeps muting and getting stuck my hammers... how could I fix it? Is it a regulation issue of the pedal system or could it be something else? Thanks
That's not a sostenuto pedal. It's a practice pedal.
Sostenuto works in a way that it keeps the dampers off the strings that are sounding at that moment. Like a sustain pedal, but only for specific strings.
What you have is a pedal which is attached to a lever which brings a curtain of felt between strings and hammers. It effectively dampens the sound when played, and works on all strings together. It's lockable - a sostenuto pedal isn't.
It is a simple mechanism, working on levers, so maybe a joint has seized up, and needs a little oil to lubricate it. You should be able to see how it all moves (or doesn't!) with the front of the piano off, revealing the strings, hammers and mechanism.
Oh i get it... sorry for the mistake. Thanks a lot for your answer, i will look it up because i have two keys that aren't playing. When i step on it the sistem goes down but when i release it it doesn't gets entirely back on position. Could it be maybe an issue of regulation of the screw that attach the wood bar to the pedal or is it something behind the entire hammer system or the curtain of felt? I've tried almost everything, even adding and extra washer to one side of the curtain so it stops moving downwards but nothing it's working. It's driving me mad– ConcordDec 31, 2018 at 17:38
If all else fails, read the instructions! If that fails, call in the experts!– TimDec 31, 2018 at 17:43