Drained hydraulic tank oil in order to service/clean the hydraulic oil strainer which is located inside the hydraulic oil tank. The strainer is suppose to thread onto the elbow leading the the hydraulic fluid supply line. The strainer was not screwed in place and was actually laying in the bottom of the tank Also, there is a plastic hose stuck in the elbow leading to the supply line. Is this plastic hose/tube supposed to be there?