check to make sure your fluid level isn't overfilled when the fluid gets hot it expands and if its overfull it has no where to go so it will apply the brakes. This is true with all cars and trucks and is the reason why its a bad idea to top off your brake fluid because if you have a clear master cylinder resivour you can look at it and know when your brakes are getting low and will prevent the brake lamp from coming on as well.
