I have an 8 bay self service car wash. I am not getting high pressure soap to 4 bays. All bays pull from the same soap tank and the lines nor port seem to be clogged. The wash is about 40 years old just so you might have an idea of how it is set up ( 8 pump stands with CAT pumps and electronics for each bay). The soap seems fine in bays 1-4 then the next 4 bays spray water but no soap. My knowledge about how It all works is a little limited but any suggestions about what the problem might be?