The integral brake is a parking brake that is on the inside of a disk brake system . This system use cables to engage the parking brake just the same a drum brake system.
Make sure there is slack in the parking brake cable. Then, hit the drum with a bfh.
Cables frozen? Return spring inside brake drum broken?
First off, you need to take any tension out of the parking brake cable. If it is still siezed up you need to work the parking brake actuator back and forth at the wheel until it frees up. If it is still siezed up hit the brake drum with a large hammer as you pull on on the drum. If it is still seized up take cut the drum off with a torch.
Drum brake? Broken return spring? Bad self-adjuster? Parking brake not adjusted properly? Disc Brake? Frozen caliper? Parking brake not adjusted properly?
should just pull off if parking brake not engaged
No , disk brakes front and rear ( the back disk brake rotors have small parking brake shoes inside of a drum portion )
The parking brake or brake cable can seize, or the shoes can rust to the drum if the car has not moved in a very long time.
Rear disc ? if it is rear disc brakes there is a drum brake in side of the rear rotor that is your parking brake and has an adjuster in it if you pull the rotor off.
Raise and support vehicle and remove wheel.Release parking brake.Remove brake drum. If drum is difficult to remove, screw in bolt to pull drum out.Remove retainer, return springs, adjuster and shoes.Remove retainer ring with suitable tool, then separate toggle lever and brake shoe.Reverse procedure to install.Adjust brakes and parking brake.
Jut pull of drum if not 4 wd, make sure parking brake off and you may have to tap it a couple times.
if your van has rear drum brakes, adjust them up until there is a slight drag on the brakes. this usually does the trick to tighten up the parking brake.