You want the slide/s EXTENDED and the Jacks retracted to check the fluid level. HWH has 2 versions of fluid level for slides. But, MOST will want the slides extended. Below is from HWH. Doug
Should my jacks and rooms be retracted to check fluid level?
If ALL the HYD oil is not back in the reservoir. You will not know if it needs oil or not. Every HYD system I have worked on. Had to be checked closed up. Jacks retracted.
If not when you do close it up. Oil will be coming out of the vent on the tank when you do close it up.
