* Broken suspension component: A broken spring, shock absorber, control arm, or other suspension part could cause a loud bang when braking. The braking force puts extra stress on these components, and a weakened part might fail.
* Brake caliper issues: A seized or sticking brake caliper could cause uneven braking, leading to a bang as a wheel locks up or a component is stressed.
* Brake rotor or drum failure: A cracked brake rotor (disc brakes) or drum (drum brakes) could shatter under braking force. This is a very serious and dangerous situation.
* Steering component failure: While less likely directly linked to braking, a worn or damaged steering component could be stressed enough by the braking force to fail with a loud bang.
* Exhaust system contact: While less likely to *cause* the stop, a loose or damaged exhaust system could make contact with other components under the stress of braking, producing a loud bang. This wouldn't necessarily stop the vehicle unless something else was also wrong.
* Something loose under the vehicle: It's possible something relatively minor (like a loose rock or debris) got wedged and was dislodged during braking. However, given the description of the car stopping, this is less likely the primary cause.
It's absolutely vital to have this checked by a mechanic immediately. Driving a vehicle with this kind of problem is extremely dangerous. The bang could indicate a catastrophic failure that could result in loss of control or an accident. Do not attempt to diagnose or repair this yourself.
