Dean, I have my hydraulic pump located in my Legacy kit #166 behind the aft bulkhead and my battery behind the passenger seat.  This, in conjunction with a 100 amp alternator, provides a CG that is too far forward.  I run out of nose-up trim during landing when solo and with light fuel. The pump has required no special servicing so far other than the annual inspection and I don't think I've had to add any hydraulic fluid in the 3.5 years I've been flying.  For this reason, locating the pump behind the aft bulkhead has not been a problem. Jim Thomas