Hooked up hydraulic hoses, followed instructions in T320 manual for backhoe operation, pulled "trigger" on right hand control, hose jumped but nothing on backhoe works - boom - bucket - etc. Checked sintered brass inlet filter and clean (actually looks new) Have grapple bucket for T320 and works fine. Just bought backhoe attachment first of this week. Reading about open center or closed center hydraulic system but totally greek to me. Can anyone steer me in the right direction?