On my trip this week to the Eastern Sierras my cabover was lifting at least 3" on the front from the winds/speeds. I had to use tie-downs from the tops of the hyd. cylinders to the dinette seat mounts to stop it from happening. My pump valve was closed and the only way this could have happened was the cylinder seals were not sealing properly??? I just replaced the O-rings and have no leaks and they lift fine. Anyone else have this problem? Any solutions other than tie-downs?