MF 135 - arms won't lift. Only will lift if I put postion and draft controls fully up postion, then (with draft control spring removed) reach in with a rod and push on the end of the draft control rod. Arms will raise then when I release the pressure on the rod, the arms lower. I replaced the draft spring assembly since the old one was loose and corroded. I am not familiar with hydrolic mechanics and not sure how to trouble shoot. Any ideas/help appreciated, thanks.