I have a 2000 National Seaview, The levelers won't go down so I did the following. I checked and filled fluid, I checked all fuses at control panel and the 10 amp fuse on the wire harness. I can hear the pump running but not making the louder noise it makes when jacks are extending. I allowed the pump run for 20 seconds by pushing individually all four buttons and then checked the fluid level, I did this again several times until the fluid level stabilized. The back jacks finally went down once but didn't when I retracted them and tried again. I'm guessing the controller but maybe someone has a better idea before I try that.