Sounds like you need to replace your Calipers at at least one of them if both are not heating up. The piton in the caniper is likely siezed common problem on any vehicle.
Could be lube/oily substance on the pads.
Either you tightened your brakes too tight or you assembled your drums wrong.
One of your brakes may be stuck. If your not mechanically inclined take your car to a brake person ASAP.
I sincerely hope you're talking about a car. If you are, check your brakes. If you aren't, see a Doctor.
what is the causes of smoke belching
What color is the smoke? Black - running rich. Bluish - buring oil. White - burning coolant. When you smell the gas, it is inside or outside the minivan? Back of the car or near the front?
The smoke.
The calipers are stuck, or they are cheap brakes, or somebody got oil or grease on the brakes and disks.
Frozen brake caliper
Smoke causes air pollution and then causes global warming. It then causes ozone depletion.
The brakes are not releasing and need to be brought back to whoever put them on.
The main cause of motorbike smoke is when the diesel is being burned and used in the engine. This smoke causes pollution to the environment.