When push come to shove and all or some of the above suggestions don't work, a sure method to undo the jacks so that you can raise them is to carefully and slowly loosen the hose connection to each jack and the pressure will be relieved so each jack can be manually raised. After this is done you would want to secure each jack in an upward position so they don't lower again until necessary as in when you reach a service center. Be ready for a bit of fluid to run out when the hoses are loosened but it shouldn't be a whole lot. When the pressure is taken off the jacks the vehicle will then lower and be prepared for that. It shouldn't be a whole lot until the tires take over the job of supporting the vehicle. I have the BigFoot Platinum model on my class C also and they are not trouble free.
