I have a National Marlin 2001. It was made only that one year on a Spartan chassis. I have Power Gear hydraulic levelers. I level the vehicle per the instructions but have no way to dump the air from the suspension. Right to left leveling is done only with the rear jacks, the front jacks are pivot points. I am thinking I should be able to dump the suspension air but I can't. This results in twisting of the frame and my windshields break in the lower corners. Any help would be appreciated.