just take it to the bike shop. I know everyone like to DIY these days but... this is a nice bike and you are talking about your brakes. a good mechanic might notice something you could miss.
yes thehousing is the black covering and they comne in either a set (cable housing0 or seperate.
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“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk