Symptoms
- Wet spot or spray pattern along a hose or at its connection point
- Coolant residue or crust built up around a hose clamp
- Coolant level dropping
- Possible hissing sound if the leak is active while the engine runs
Likely causes
- CommonCracked or split hose from age and heat cyclingRubber hoses harden and crack over years of heat exposure, eventually failing at a weak point.
- CommonLoose or corroded hose clampClamps can loosen over time or corrode, no longer sealing the hose tightly to its fitting.
- PossibleWorn hose end where it meets a metal fittingThe area right at the connection sees the most stress and often wears first.
- Less commonChafing from contact with another partA hose rubbing against a bracket or another component can wear through over time.
What to do
- Visually inspect all visible coolant hoses for cracks, bulges, or wet spots with the engine cool.
- Check each hose clamp for tightness and corrosion, and gently squeeze hoses (when cool) to feel for soft or brittle spots.
- Note the exact hose and location of any leak found for the repair.
- Avoid squeezing or manipulating a hot hose or system, since it may be pressurized.
- Have a mechanic replace the specific leaking hose and its clamps, rather than just tightening a clamp on a hose that's otherwise degraded.
- Flush and refill the system with the correct coolant after hose replacement.
- Check for leaks again after a short test drive, once the engine has reached normal operating temperature and pressure.
Tools and parts
- Flashlight
- Screwdriver or hose clamp pliers
Radiator hoseSearch: “radiator hose for [make model year]”
When to call a pro
See a mechanic if you're not comfortable draining and refilling coolant yourself, since air needs to be properly purged from the system after hose replacement.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.