Warped rotors. Driving using the left foot to brake causes the rotors to heat up. Quenching the hot rotors by driving thru water will cause them to warp. The warped rotors cause the pedal to pulsate.
The front rotors are out of round or warped, Need to have the rotors turned.
Do you have anti lock brakes that might be it if not your rotors maybe warped
You have warped the brake rotors. Driving fast & hard stopping or riding the brake will cause this when the rotor is hot and you are stopped with heavy pressure on the brake pedal. Replace rotors and pads.
The rotors are out of round, WARPED. Need to have them turned and replace pads too.
The most common cause of that is the front brake rotors are out of round / warped. Replace rotors are have them turned.
For the brakes, check for warped rotors. For the turning, check for worn CV joints.
A common reason is that the front rotors have warped. Go check out WikiAnswers on the topic of "warped brake rotors". Rotors should wear out smoothly in normal driving. Use of the brakes that generate lots of heat (hard braking, riding the brakes) will result in warped rotors.
sounds like warped or worn rotors to me
The warpage makes the brake pedal pulsate, which doesn't usually interfere too much with braking, but why take chances with anything but top condition for your stopping power?
No, warped rotors will cause vibration when braking.
If you're changing the brake pads and there is too little rotor thikness to turn it, it should be replaced. If the rotor is warped and is too thin to be able to turn to remove the warping, replace it. If the brakes "pulsate" when you use moderate brake pressure, the rotor is warped.