One or more rear wheels dragging when trying to pull away. Normally after heavy rain or vehicle being left for a long period of time. Note tyre drag line in picture.
1. First try rocking car backwards and forwards vigorously in first and reverse gears, if you are lucky you will hear a bang and the brake will release.
2. Try rocking car to left and right with hand brake off be sure to chock wheels or leave in gear, as vehicle might suddenly un-jam and roll.
3. The next step is to remove the wheel with the jammed brake (see wheel change if unsure of wheel removal)
4. With a front wheel chocked and in gear or park remove hand brake, using a soft hammer hit the brake drum between the wheel fixings, the shock should release the drum and it should now turn freely.
5. Engage handbrake, refit wheel and take for a drive using the brakes as much as possible to remove the rust in brake drum.
6. If car has not had the rear brakes checked for 10,000 miles or so, you may have excessive dust built up in the drum and would recommend full brake check, however if car is fully serviced don’t worry it is just a problem you can have in bad weather.