Not sure if your leveling system is the same as mine, but mine is made by Dewald or Power Gear and it's hydraulic. You might start with the simple stuff such as making sure there is enough fluid and the screws on the pump assembly are tight. Here are some info:
http://www.powergearus.com/DATA/82-l0377.pdf
If that didn't solve your problem, try this more detailed document:
http://www.powergearus.com/DATA/part...e_footpads.pdf