Sorry for the delay.
If pumping the pedal does not make any differences, you are correct about the ABS accumulator being the culprit but it is not air in the system that is causing this. In fact it is due to lack of back pressure.
One way of doing it is to get a scan tool to perform bleeding of the ABS system.
Try this, drive vehicle on a sandy patch and press the pedal hard to jam the brakes. The accumulator should work, keep repeating until the pedal becomes firm.
Thursday, May 20th, 2021 AT 10:39 AM