Instead of just flushing the D. with water, try pumping/recycling 2 gallons of Vinegar through the pump for a couple of minutes to disolve and clean out the SH crystals that collect inside the pump. (Pour them into a 5 gal bucket and have the input/outflow tubes in the same bucket.)
Mine was running poorly and had eventually lost prime. Called The Man, Bob, and he told me about it. Had to take apart the input hose and funnel Vinegar into the pump - as it had lost prime - but after several frustrating minutes it started to drawl and eventually it worked like new.
My D. is trailer mounted and used to transfer SH to my main tank only; Bandit for spraying. I changed trucks and the new one does not run the D. as well as the old one. I assume the wiring is different (smaller gauge or too many feeders to other components) and have to change it or run a line directly from the battery to get it running right.
***Updated*** Just bought a deep cell marine battery and hooked it up like it is posted on the site - 3 feet from the D., etc and I was Shocked at how much faster the D. ran! That pump really does have some power! The van hook up stunk and the truck was ok, but nothing compared to this. Thanks for the tip!
