Kia Sedona: Adjusting the height up and down
To raise the headrest, pull it up to the desired position (1). To lower the headrest, push and hold the release button (2) on the headrest support and lower the headrest to the desired position (3).

✽ NOTICE
If you recline the seatback towards the front with the headrest and seat cushion raised, the headrest may come in contact with the sunvisor or other parts of the vehicle.
Headrest (for front seat)
Removal and reinstallationSpark Plug Specifications
Specification
ItemSpecificationTypeSILZKR7B11Gap1.0 ~ 1.1 mm(0.0394 ~ 0.0433 in.)Insulation resistance (MΩ)10 or more
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Brake Lines, Hoses and Connections Repair procedures
Inspection
Visually check for proper installation, chafing, cracks, deterioration and any leakage.
Replace any deteriorated or damaged parts immediately. ...