Chkdsk in read-only mode does not repair - it's only a quick gude which may or not report correctly.
You'd be better off running chkdsk as chkdsk /f which repairs files and will report if it finds any bad sectors or use chkdsk /r which will move and repair corrupt data from bad sectors, but cannot repair those sectors - it only prevents data from being written to those sectors in the future.
If a chkdsk /r reports KBs in bad sectors, you may have some leeway in its continued use but the hard drive will eventually fail, sooner rather than later and you should have your whole system backed up in a system image for when it does.