I have a forty foot motorhome that is our first. I had a problem on our last trip breaking camp. Getting ready to go I raised all four jacks but the front left was fully retracted but sitting on the block I used due to having a low corner on our site. Once I set the block down under the jack when setting up, there was one and one quarter inch of space between the pad and wood block. When getting ready to leave I raised the jacks and started the engine to fill the airbags but the coach remained on top of the block. What happened to the one and one quarter inch space I had? We had to dig and chip away at gravel to get the block out. Is there something I am doing incorrectlyY. Thanks for any help.