this is a mtn bike? before you took the back wheel off did you release the quick release on the brakes? did the person who reinstalled the wheel do it? I think you may have moved the position of your brake pads when taking the wheel off. or a the cable is just caught up somewhere.
can you post a few pics? a pic of the lever, the rear brakes and wheel?
PS; 10:44 on a warm spring Sunday is a slow period so it may take 30 or longer for someone to see you post. and perhaps some read it and just could not think of an answer
PSS; OH a disc brake....
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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