One or more of the brake rotors are warped from heat, caused by braking. Riding the brakes or always being on them, are usually the cause.
IT COULD BE A WORN ENGINE MOUNT. TO BE SURE, PUT YOU CAR IN GEAR PRESS THE BRAKE APPLY THE E-BRAKE AND ACCELERATE THE CAR IF YOU FEEL THE SAME SHAKING IS YOUR ENGINE MOUNTS. (BE Careful)
Warped rotors is the most likely cause. Seek professional help.
A faulty power brake vacuum booster could do that.
It's not so much the "car shaking" as it is feedback through your foot from the brake hydraulic system. YOU are shaking -- at least your foot is -- and you're assuming that it's the car. Most likely, your car is equipped with disc brakes on the front, possibly on the rear also. Disc brake rotors warp. It usually happens due to overheating, but it can be the result of a manufacturing defect. The "thumping" effect is a real attention-getter!
It could be that one of your brake discs is is bent this happend to my Ford Telstar which is just a rebadged 626, if the shaking is more orientated to a corner of the car that's your problem, if the whole car shakes I have no clue sorry
A car shaking while applying brakes is most likely caused by worn a brake pad. Check the brake system at all four wheels to find the problem.
brake shoes or pads are worn and need replacing
the cuase of this is ussaully worped rotars
The most common causes of overheating and shaking in a vehicle are the head gaskets. A blown head gasket will produce overheating and shaking and may lead to a cracked head.
Stop driving your car asap.It means there is a brake fluid leak.Get your car towed to a mechanic.
Check your tires to make sure there are not out of round and properly balance.
Bulbs, wiring, fuse, brake light switch.