This procedure covers the replacement of the radiator cap on a 2016-2024 Hyundai Tucson with the 2.5L I4 engine. This is a simple maintenance task requiring minimal tools and time.

Warnings

Tools required

Parts

• Radiator cap × 1 — Use OEM Hyundai/Kia specification, typically 1.1 bar (16 PSI) rating

Preparation

1. Ensure the engine has been off for at least 2 hours and is completely cold
2. Park the vehicle on level ground and engage the parking brake
3. Open the hood and locate the radiator cap on the radiator neck, positioned on the driver's side of the radiator

Procedure

1. 1

   Verify engine temperature
   Touch the radiator cap and upper radiator hose to confirm they are cool to the touch. If there is any warmth, wait longer before proceeding.
2. 2

   Relieve pressure slowly
   Place a shop towel over the radiator cap. Slowly turn the cap counterclockwise to the first stop (approximately 1/4 turn) and pause. This allows any residual pressure to escape safely. Listen for hissing sounds and wait until all pressure is released.
3. 3

   Remove the old radiator cap
   Once pressure is fully released, continue turning the cap counterclockwise while pressing down slightly until it can be lifted off the radiator neck. Remove the cap and inspect the radiator neck seal surface for damage or debris.
4. 4

   Inspect coolant level and condition
   Look into the radiator opening to verify coolant level is visible near the top. Check that coolant is green in color (Hyundai/Kia Long Life Coolant) and free of contamination, rust, or oil. If coolant level is low or contaminated, further service is required.
5. 5

   Clean the radiator neck
   Use a clean shop towel to wipe the radiator neck sealing surface, removing any dirt, debris, or old coolant residue. Ensure the surface is clean and smooth for proper cap sealing.
6. 6

   Install the new radiator cap
   Remove the new radiator cap from its packaging and inspect the rubber seal for damage. Align the cap with the radiator neck, press down firmly, and turn clockwise until it stops at the locked position. You should feel a positive click or resistance when fully seated.

Reassembly

1. Ensure the radiator cap is fully seated and locked in position
2. Wipe away any coolant residue from the radiator or surrounding components

Verification

• Start the engine and allow it to reach normal operating temperature while monitoring for leaks around the radiator cap
• Check that the overflow tank shows coolant at the proper level between MIN and MAX marks
• After a test drive, recheck the radiator cap area for signs of coolant seepage or pressure loss
• Verify no warning lights appear on the instrument cluster related to cooling system operation

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