vertical dampers

[Brenda Mamer]

Hi List,
I have a piano teacher with a 15 yr. old  Kawai vertical UST7.  It has a
general 'ringing'.  Pedal has some lost motion, dampers seem to be
following the strings.  Wondering if people have been replacing these
dampers with  newer, perhaps longer dampers?  Does this seem to be
common with this model piano?  She has it backed up to the corner of
her room, not against the wall.  Wondering if this might exaggerate the
ringing?
                                        Thanks in advance,

                                                    Brenda Mamer, RPT
WI