Pro bono opportunities during the summer?

I want to get involved in pro bono during the summer but can’t find anything that isn’t linked to a university of law school.

I am a 2nd year law student at Cambridge University. I read an recent article on pro bono work and was really inspired. Though I have come across pro bono work and such opportunities, it’s very difficult to get involved during the intense eight week terms at university. Instead I’ve been looking for a pro bono placement in Manchester for the summer months – August and September, but it’s very difficult to find one unless you’re associated with the law school or the university. Does anyone have any suggestions? I’ve recently tried to contact the local CAB but they seem to require a minimum of six months commitment, but this becomes really impossible as I don’t live in either Manchester or Cambridge for a whole continuous six months.