The safest (and most warranty-wise) answer: Do what your rig's manual tells you to do. Here's a lift from a Keystone manual: "The recreational vehicle must be level to avoid binding the slide-rooms. Remember, stabilizing jacks are not capable of supporting the weight of you vehicle! They are intended only to stabilize the unit maintaining a level condition. Non-leveled conditions cause sticking situations providing damaging strains on the slide-out mechanism."
|Courtesy U.S. Patent Office|
OK, so much for the simple answer. Now things can get a bit more complicated than "what the book says." What about that "leaning RV." What can you do about that situation? If your rig leans after you deploy the slide-out, the most likely issue was not having your unit properly settled in the first place. Were the levelers on firm ground, or did they perhaps "sink" a bit into soft ground? Here's a case for leveler or "jack boots" that give a larger surface area to those little feet.
If you're leaning over, take a good look at your site, and peek around underneath the rig. If the leaning is such that the rig isn't comfortable, or enough that it could cause damage to your refrigerator there may be no help for it but to pull up stakes and move the rig a bit, settling in on 'terra' that's a bit more 'firma.'