Repair Lane

Radiator Cap Replacement

A worn radiator or reservoir cap is tested and replaced — one of the cheapest fixes for coolant loss and overheating.

Difficulty: easy~0.20.4 hrs15–30 minutes
Estimated total
$35–110
Parts$10–40
Labor$25–70
Labor time0.20.4 hrs
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What's involved

What this repair actually is.

The radiator cap holds the cooling system at the correct pressure, which raises the coolant's boiling point. When the cap's seal or spring wears out, coolant boils over or seeps out and the engine can overheat. We test the old cap and install a new one matched to your system's pressure rating.

Symptoms

How you can tell.

  • Coolant overflowing from the reservoir
  • Coolant slowly disappearing with no visible leak
  • Dried white or green crust around the cap
  • Occasional overheating in traffic
If you delay

A bad cap lets coolant boil off until the engine overheats, risking far more expensive damage than the cost of a cap.

Educational estimate. Real pricing depends on your vehicle, the inspection, parts availability, taxes, and shop rates. Use this as a guide while you shop quotes.
Related

Often done together.