Check the front and rear GVWR on your motorhome. On my short 25 foot class A the rear axle rating is 7500 pounds, or 1500 pounds over the max rating for that jack you are talking about. Even my front is almost 4900 pounds. Remember the closer you get to the max weight on the jack, the harder it is going to be to pump it up, and the harder it is on the jack. When I did my brakes, I used a floor jack to slightly raise each corner, then used a twenty ton bottle jack to get it off the ground. Also make sure you have jack stands that will handle the weight. The wimpy stamped steel automotive ones aren't heavy enough.