2001 GMC Sierra 1500 Pickup Owner's Manual - Page 21

On some models, the head restraints tilt forward and rearward also. To tilt the head restraints forward, grasp the top of the restraint and move it forward to where you want it to go until you hear a click. It will then be locked into that position until you need to move it again. Pulling it forward past the last position will allow the restraint to return to its upright position. The seatbacks fold forward to let you access the rear of the cab. To fold a front seatback forward, pull this lever toward the front of the vehicle to release the seatback. The lever is located on the outboard side of the seat cushion. Seatback Latches CAUTION: If the seatback isn't locked, it could move forward in a sudden stop or crash. That could cause injury to the person sitting there. Always press rearward on the seatback to be sure it is locked. To return the seatback to the upright position, push the seatback rearward until it latches. After returning the seatback to its upright position, try to pull the seatback forward to make sure it is locked. 1-8