ductedfan,
If all 4 of your jacks wouldn't lift then it would be the dump valve. My problem only exist on the rear jacks. Please let me know if your problem was all 4 or just one side. I removed all the solenoids today and they did not look visibly worn. All of them looked to be in the same condition. What did your worn valve look like? What was bad on it? The dump valve on my RV is not the same as the fill valves but I will try to swap the front valve with one of the rears. What I find hard to believe is that both the rear valves are bad. Also, on my system the valves are made by Hydac and I actually found the exact valve on their product catalog. I plan to call them tomorrow and ask them if the valves are bad. They also sell seal kits for the valves in Buna and Viton. Since the valves still actuate, I hope the seal kit is all they need (I will get the Viton better rubber) but again I find hard to believe is that both the rear valves are bad.