Hopeful somebody can help clear this up! I have a automatic and when the car first pulls in it has a undercarriage wash it sprays and the pressure guage takes a second before it get up to 1000psi I think I heard the Unloader sounded like it was pushing what sounded to be air? Then when car pulls on in it starts again at the 1000 psi but the guage kinda bounces back and forth like 1000psi down to 900psi! And ideas pump problem or Unloader?
