Hi Terryshirley..... Cpl.Ed here,
Just a little clarification on the bombings. My uncle's plane was "The Great Artiste", which he flew on the Hiroshima run. When it came time to fly the second bombing run the Artiste had mechanical issues. They hurriedly prepared the "Bock's Car", named because the pilot was Major Bock, to carry the payload. It took quite some time because the stock B-29 couldn't handle the size and weight of the bomb. Uncle Charley spent the entire war training for this one combat mission. It's all in the book, very interesting.
I have the same problem on my Winnebago Ultimate freedom. My system is HWH 610. Have not checked fuses yet, but raised the jacks by draining the hydraulic lines (the default is to store when pressure is lost). Please let me know what you determine.