It looks like, if you have ABS, this may be "normal".

SYMPTOM
CONDITION
Pulsing brake lever or pedal during an ABS event
Normal condition.
Clicking sound during an ABS event
Normal condition.
ABS lamp flashing
Normal condition - key turned to IGNITION - speed under 3 mph 5 km/h .
Perceived "surge" while braking
Normal condition - most noticeable when braking with one brake (front only or rear only). Result of a reduction in deceleration which can be caused by cracks or bumps in road, engine braking (high engine RPMs causing the rear wheel to slow down), hard braking at slow speeds, and other conditions. This is due to ABS modulating caliper brake pressure to prevent uncontrolled wheel lock.
Temporarily stiff rear brake pedal
Normal condition - engine braking (high engine RPMs causing the rear wheel to slow down) or down shifting can activate ABS. If applying the rear brake at the same time or immediately after, the ABS may be closing a valve to prevent pressure to the rear brake. This is due to ABS modulating caliper brake pressure to prevent uncontrolled wheel lock.
Tire chirp
Normal condition - depending on surface, tire can chirp without locking the wheel.
Black mark on pavement
Normal condition - depending on surface, tire can leave a black mark without locking the wheel.
Wheel lock at low speed
Normal condition - ABS will not activate on front wheel below 3 mph 5 km/h

 

And your point is??

 

 

Warped Rotor. i had that same surge on my 2011 limited. i replaced the stock front rotors with Lyndall Carbon Fiber rotors and now no surge and it stops on a dime. it now has so much stopping power i can cause my own ABS event. and that will open your eyes