Problem: The shop had replaced the HCU and attempted to bleed the brakes with Ford IDS scan tool and pressure bleeder. On numerous attempts, they kept getting scan tool error “06” when bleeding last wheel (Left Front Wheel).
Details: The OE instructions state that, when bleeding the brakes at the last wheel, you are required to pump the pedal 30 times – All the other wheels require you to pump the pedal 10 times. The ALLDATA Tech-Assist Consultant advised that the problem may be that the hose between the pressure bleeder and the master cylinder reservoir was not a large enough ID (inside diameter) to keep up with the demand for fluid volume, while maintaining the correct pressure.
Confirmed Repair: The tech installed a larger ID hose and the system was able to be bled properly. Ford says to have 1 ½ gallons of brake fluid available for this procedure. When the tech used the correct ID hose, most of that amount was used.