The brake pedal of my friend's Nissan Terrano becomes spongy for short period of time while braking over bumps and the braking doesn't seem to slow down the vehicle for a short time.Braking under normal conditions is OK but it's not so on bumps.I was trying to understand why the abs activates on bumps.
What are the methods to determine experimentally when the abs of a car is activated and the duration over which it remains active during braking?
