What the hell gives you the idea that there's a memory leak?
Let's see...
Lempster (3/6/2014)
http://www.sqlskills.com/blogs/jonathan/how-much-memory-does-my-sql-server-actually-need/
GilaMonster (3/11/2014)
Chapter 4: http://www.red-gate.com/community/books/accidental-dba
Go and do some reading on how SQL uses its memory and how to monitor the memory.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability