when i slam my brakes, do all four wheel brakes get locked or just the front two wheels?

Applying the brake pedal will activate brakes on all four wheels. The braking effort will be applied with greater force on the front wheels as this is the most effective way of stopping the car.

The reason that the handbrake works on the rear wheels is convention. When (the more powerful) disc brakes were introduced it was difficult to get the handbrake to work on them. However the rear brakes were usually still drum brakes and handbrakes work well on these, and thats how it came about.

Some handbrakes do work on the front brakes, it depends on the make and model.

All 4 wheels are braked by the foot brake

More effort is to the front wheels than the rear.

With ABS nothing should just lock.

The brake pedal applies brakes on all four wheels at the same time. The handbrake secures just two wheels by a mechanical linkage. This is usually the rear two though in some cases it can be the front.

Your "FRIENDS" are automotive S...heads! The BEST cars use th rear brakes FIRST to stop the rear of the car and then ADD the front ones slightly later. THis preents your head from being thrown through the windhsiled. ALL FOUR brakes are use ALL the time. THe best cars SENSE what you are doing and apply brakes as necessary to keep you from being propelled through the GLASS! THen add in ABS brakes to boot to use a computer to stop wheel spinning in various road conditions.

all four will lock because they all have brakes operated by hydraulic cylinders

the brake pedal operates the brakes on all 4 wheels the handbrake only secures the vehicle when your not in it so it doesn't roll away. Notice drifters set up a handbrake system that operates the brake calipers on the rear wheels as the handbrake wont last if you were doing handbrake turns too often.

the brake pedal operates the brakes on all 4 wheels the handbrake only secures the vehicle when your not in it so it doesn't roll away. Notice drifters set up a handbrake system that operates the brake calipers on the rear wheels as the handbrake wont last if you were doing handbrake turns too often.