Mark vii spot free

[DDWASH]

I have a Mark VII that works fine until you use the spot free. When the spot free is activated it fills the main tank until it overflows into the bay. I replace the control valve but that did not change anything. I seams to not build up enough pressure to block of the back flow control valve. Has anyone had this problem. Kinda dead ended?

 

[I.B. Washincars]

Need more info. What model machine is it? Does it have a PVC check or the Aqua-Matic??? valves?

 

[DDWASH]

GT300 Aqua-Matic valve. The pressure at the pump of the spot free starts at 30-35 at start up and increases to 50-60 then levels off at 50psi and holds that pressure until sartup again. thanks