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Coolant Expansion Tank

As engine coolant heats up, it expands. The coolant expansion tank provides additional storage for the expanding coolant and is commonly the location where coolant is added to the engine.

Symptoms of Wear or Failure

  • Engine coolant leak
  • Engine overheating
  • Coolant may boil over
  • Illumination of the low coolant warning light

Related Repair Advice

  • The coolant cap should not be removed from a pressurized expansion tank when the engine is warm
  • The coolant level in the expansion tank should be checked every other time the gas tank is filled
  • We highly recommend replacing the coolant cap when replacing the expansion tank
  • If the coolant level in the expansion tank consistently drops after topping off, there is probably a leak
  • Failure of the low coolant sensor may require replacement of the expansion tank

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