[John2000] You might try raising or lowering the front of the RV depending on which side of the outlet the tank is on, i.e., if the tank is to the rear of the valve, lower the front of RV. Likewise you might want to be sure the side opposite the valves is a tad higher than the valve side of the RV. Of course I don't believe the tank needs to be completely dry. Just close the valves and drain the hose by disconnecting and raising the end away from the dump. Hope that helps.
[jmerritt] You might want to try back flushing the tanks just to be sure you don't have any blockage. Once you have finished draining a tank, leave the valve open aand raise the end of the drain hose and run water into the hose backfilling the tank. CAREFULLY lower the hose to the drain. Repeat until you are satisfied the tank is draining OK. I want to emphasize the word CAREFUL since you don't want any surprises when doing this!
[bigdumbsquirrel] The jacks are more valuable than to just level the MH. I'll bet that tilting and back flushing will work. My previous MH didn't have Hyd jacks and I didn't think of utilizing them to solve my problem. Thank you both very much.