OK, let's try this one. One of my customers has this machine and if it sits for a day or two between washes, the first pass of presoak is water only. The foot valve for the chemical supply line is good and the line is filled with soap. It just takes one revolution before soap comes out. The washes after that are just fine, with only a short, maybe 5 second, time for the wand to fill. Any thoughts? And the reason it sometimes sits for a day or two between washes is rain. Lots of rain.