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 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?
what is the causes of smoke belching
The smoke.
Frozen brake caliper
The calipers are stuck, or they are cheap brakes, or somebody got oil or grease on the brakes and disks.
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.
my daughter has a 98 neon and it had the same exact problem. What i found was that the left front rubber line was so old that it was collapsing when the brakes got up to operating temp in essence making the brake drag until it almost locked. She got it so hot it melted the hubcap. I replaced with new rubber line and haven't had the problem since.