I’m working on a friends 2010 Dodge Journey 3.5 v6 2wd that has a soft brake pedal when running but firms up when Engine is off. While driving, The pedal will go nearly to the floor before the brakes grab but still stops good. There are no visible leaks anywhere, lines and calipers are all dry. Car has new pads front and rear, new front brake caliper hoses, new master cylinder and new booster. All four corners were bled with a pressure bleeder, went for a drive and made a few panic stops on gravel to engage the abs, then bled the brakes again. All of this and still no change in the pedal feel.
What I’ve done is looped the lines at the master cylinder with a spare piece of brake line, started the car and had a good firm pedal. So the new master cylinder is good and holding pressure. Then I removed the loop, hooked the lines back up and clamped the rubber hoses at all four wheels and had a soft pedal again. This leads me to believe that the abs hydraulic unit is bad as it’s the only thing between the master cylinder and hoses. Can anyone confirm my diagnosis or offer any more advice? Anyone changed the abs unit before and have any tips? Thanks in advance for any help you can offer!