Repairing a Broken Plastic Upper Radiator Neck

Jul 6, 2022


Welcome to Grafco Electric, your go-to resource for all your automotive repair needs. In this comprehensive guide, we will walk you through the detailed process of repairing a broken plastic upper radiator neck. With our step-by-step video guide and professional tips, you'll be able to fix your radiator neck effectively and save money on costly repairs.

Understanding the Problem

A broken plastic upper radiator neck can be a nuisance and lead to coolant leaks, engine overheating, and potential vehicle damage if not addressed promptly. The plastic neck is vulnerable to stress, age, and wear, often resulting in cracks or fractures. Ignoring this issue can lead to more severe engine problems, so it's essential to take action as soon as you notice any signs of damage.

Tools and Materials Required

  • Replacement Upper Radiator Neck
  • Plastic Welding Kit or Epoxy Resin
  • Screwdriver Set
  • Socket Wrench Set
  • Radiator Coolant
  • Protective Gloves
  • Safety Glasses

Step-by-Step Repair Process

Step 1: Preparation

The first step in repairing a broken plastic upper radiator neck is to ensure you have all the necessary tools and replacement parts. Make sure to gather everything before you begin the repair process to save time and avoid any unnecessary delays. It's also crucial to take safety precautions and wear protective gloves and safety glasses to protect yourself during the repair.

Step 2: Drain the Coolant

Prior to removing the broken radiator neck, it's essential to drain the coolant from the radiator. Locate the drain plug or valve at the bottom of the radiator and use a screwdriver or socket wrench to open it. Collect the coolant in a suitable container for proper disposal. Remember to follow environmental regulations when handling coolant.

Step 3: Remove the Broken Radiator Neck

Once the coolant is drained, carefully remove any hoses or clamps connected to the upper radiator neck. Use a socket wrench or screwdriver to loosen and remove the screws or bolts securing the broken neck in place. Gently lift and remove the damaged neck from the radiator without applying excessive force.

Step 4: Assessing the Damage

Before proceeding with the repair, it's crucial to assess the extent of the damage to the radiator neck and surrounding areas. Inspect for any cracks or additional fractures that may require further attention or replacement parts. Clear any debris or dirt from the radiator surface to ensure a clean and secure attachment of the new neck.

Step 5: Choose a Repair Method

Depending on the severity of the damage and resources available, you have two options for repairing the broken plastic upper radiator neck. You can either utilize a plastic welding kit or use an epoxy resin specially designed for automotive repairs. Both methods can provide effective solutions, but it's essential to choose the one that suits your skill level and the availability of tools.

Step 6: Repairing with Plastic Welding

If you opt for plastic welding, follow the manufacturer's instructions on how to use the kit. Typically, it involves heating the plastic and applying a welding rod to the broken area, fusing it back together. Ensure to heat the plastic evenly, avoid overheating, and maintain proper ventilation during the welding process. Once the repair is complete, allow sufficient time for cooling and solidification before moving to the next step.

Step 7: Repairing with Epoxy Resin

If you choose epoxy resin, mix the components according to the manufacturer's instructions. Thoroughly clean and dry the broken areas, ensuring there is no moisture or residue. Apply the epoxy resin evenly over the damage, ensuring full coverage. Follow the curing time specified by the manufacturer before proceeding to the next step.

Step 8: Reinstall the Upper Radiator Neck

Once the repair is complete and the plastic or epoxy has properly cured, it's time to reinstall the upper radiator neck. Carefully align the replacement neck with the radiator housing and insert it securely. Use a socket wrench or screwdriver to fasten the screws or bolts, ensuring a tight fit. Reattach any hoses or clamps removed earlier, following the manufacturer's guidelines.

Step 9: Refill with Coolant

With the upper radiator neck successfully repaired and reinstalled, it's time to replenish the system with radiator coolant. Pour the appropriate coolant into the radiator, following the manufacturer's recommended specifications. Do not overfill the radiator, ensuring it's at the correct level for optimal performance. Once filled, close the radiator cap and ensure it is tightly secured.

Step 10: Test for Leaks

After refilling the system, it's crucial to test for leaks and ensure the repair is successful. Start the engine and allow it to run for a few minutes. Observe the radiator area carefully for any signs of coolant leakage or irregularities. If there are no leaks and the engine temperature remains stable, your repair was successful!


Congratulations on successfully repairing your broken plastic upper radiator neck with the help of Grafco Electric. By following our comprehensive guide and utilizing our professional tips, you were able to save money on expensive repairs and ensure the proper functioning of your vehicle's cooling system. Remember to perform regular maintenance to prevent any future issues and keep your car running smoothly. If you encounter any further automotive repair challenges, we are here to assist you. Happy driving!

Regan Wynne
Really helpful tutorial! 👍
Nov 12, 2023