Slide out drifts open

My trailer has coroplast closing off the undercarriage. If you are insulated, any fluid leak could be masked or absorbed by the insulation batting. There is a feed and return line for each cylinder with 3 threaded fittings for each. So that is 6 per cylinder. If only 1 slide is slipping, then that is a starting point. Also, in a sealed system, if you are low on fluid, it is going someplace, indicating a certain leak. Remember to check the level with everything retracted, including your hydraulic landing gear. Shouldn’t be any air in an already operating system unless it was opened, or a worn part/seal. Good luck!