The seal for the left hydro pump blew on my 2001 Scag STT61. Replaced the seal but the left side would not operate. Pulled and disassembled the hydro pump and found the rotating members had rubbed and created quite a few metal shavings. Three of the pistons in the rotating cylinder would not even move due to the buildup of metal shavings in the springs. I have purchased a new BDP-10L-121 hydro pump and have a few questions before replacing. What precautions should I take prior to replacing the pump. I know I need to flush the system but how should I go about flushing the system with the pump removed. I have seen comments abouts replacing the wheel drive motor at the same time but I don't want to spend another $400 if I don't have to. Is there a way to test the wheel motor? Should I remove the wheel motor to flush? Have not seen a parts breakdown so I am not sure how/if to disassemble. Any help would be appreciated.