How to Replace A Radiator Hose

📋 Quick Facts

A swollen, bulging, or cracked radiator hose can fail at any moment and dump coolant. New hoses run $15-40 each. DIY is a 30-60 minute job on most vehicles - one of the easiest cooling fixes.

🛠 What You'll Need

• New upper or lower radiator hose (year/make/model specific) (OEM-fit radiator hose on Amazon)
• New hose clamps (worm-gear or constant-tension) (hose clamp assortment on Amazon)
• Fresh OEM-spec coolant (1-2 gallons) (coolant on Amazon)
• Drain pan (2-gallon) (drain pan on Amazon)
• Hose clamp pliers or flat-head screwdriver (hose clamp pliers on Amazon)

✅ Before You Start - Checklist

• Park on level, solid ground (no slopes, no soft dirt)
• Engine is at the correct temperature (cold or warm as specified)
• All tools and parts on hand BEFORE you begin
• Owner's manual nearby for torque specs and locations
• Safety: gloves, eye protection, hood propped open

📝 Step-by-Step Instructions

1. Cold engine confirmedTouch the upper hose - it should be at ambient temperature. Open the hood and chock the wheels.
2. Identify the failed hoseUpper hose runs from the top of the radiator to the engine (thermostat housing). Lower hose runs from the bottom of the radiator to the water pump inlet. Squeeze them - a bad hose feels mushy, swollen, or has visible cracks at the bends.
3. Open the radiator cap to release pressureTwist slowly. If you hear a hiss, the engine is still warm - wait longer.
4. Position the drain pan under the radiator drainOpen the petcock (white plastic plug at the bottom corner of the radiator). Drain into the pan. If no petcock, pull the lower hose to drain.
5. Loosen the clamps on both ends of the failed hoseWorm-gear clamps: 7mm or 8mm nut driver, or flat screwdriver. Constant-tension spring clamps: hose clamp pliers - squeeze the tabs and slide the clamp back along the hose.
6. Twist and pull the hose off each fittingIf stuck, slip a flat screwdriver between the hose and the fitting to break the bond - twist gently. Do NOT pry against plastic radiator necks (they crack).
7. Inspect the radiator and engine fittingsWipe clean. Look for cracks in the plastic radiator neck or corrosion on the metal pipe. A cracked radiator neck means the radiator itself needs replacement.
8. Compare the new hose to the old oneBends should match. Some hoses are universal flex hoses - these need to be cut to length, which is fine for emergencies but molded OEM hoses fit better.
9. Install new clamps loosely on the new hoseSlide them onto the hose before pushing it onto the fittings.
10. Push the new hose onto both fittingsTwist as you push for a tight seal. Both ends must be fully seated - at least 1 inch onto each fitting.
11. Position and tighten clampsPlace the clamp about 1/4" from the end of the hose. Tighten worm-gear clamps until snug - do not over-torque (they cut into the hose).
12. Refill the cooling systemPour fresh coolant (correct spec - green, orange, pink, blue all matter) into the radiator and overflow tank. Stop when the radiator is full.
13. Start the engine with the radiator cap offHeat to full, fan high. The thermostat opens and the level drops - top off. Squeeze the upper hose to burp air bubbles out.
14. Pressure-check by feelAfter 10 minutes of running, gently squeeze the new hose - it should be firm but not bulging. Cap the radiator.
15. Drive 10 miles and recheck coldPark overnight. The next morning, check the level cold and look under the car for drips.

✅ After You Finish - Verify Checklist

• No tools left in the engine bay or under the car
• Test the system you worked on (start, drive, check, etc.)
• Look for leaks or drips after 5 minutes of running
• Record the date and mileage in your service log
• Recycle or properly dispose of any old parts/fluids

🔗 Related Guides

❓ Frequently Asked Questions