🔧 Highlander - Radiator Hose Replacement

This repair replaces a leaking, swollen, cracked, or soft radiator hose on your Highlander. The 2.7L engine uses an upper and lower radiator hose, and the process is similar for both, but the lower hose will drain more coolant and is harder to reach.

Difficulty Level: Beginner | Estimated Time: 1-2 hours

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⚠️ Safety & Precautions

• ⚠️ Only work on the cooling system when the engine is fully cold. Hot coolant can cause serious burns.
• ⚠️ Do not remove the radiator cap or reservoir cap while the engine is hot.
• ⚠️ Keep coolant away from children and pets. It is poisonous and can taste sweet.
• ⚠️ Wear safety glasses and nitrile gloves. Coolant can irritate skin and eyes.
• ⚠️ Support your Highlander with jack stands if you raise it. Never rely on a floor jack alone.
• ⚠️ Battery disconnect is not required for this repair.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• Drain pan rated 2-gallon minimum
• Slip-joint pliers 10-inch
• Hose clamp pliers (specialty)
• Flathead screwdriver 6-inch
• 10mm socket
• 3/8-inch ratchet
• 3/8-inch extension 6-inch
• Plastic trim clip remover
• Funnel with long neck
• Clean shop towels
• Floor jack rated 3-ton minimum
• Jack stands rated 3-ton minimum

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Upper radiator hose - Qty: 1
• Lower radiator hose - Qty: 1
• Radiator hose clamps - Qty: 4
• Toyota Super Long Life Coolant 50/50 premix - Qty: 1-2 gallons
• Engine under cover clips - Qty: As needed

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📋 Before You Begin

• 🅿️ Park your Highlander on level ground and set the parking brake.
• ❄️ Let the engine cool completely. A safe wait is at least 2-3 hours after driving.
• 🧴 Use Toyota Super Long Life Coolant or an equivalent pink, phosphate-enhanced Asian vehicle coolant.
• 🪣 Place a drain pan under the radiator before loosening any hose.
• 📌 A hose clamp is the metal spring or screw clamp that squeezes the hose tight onto the radiator or engine fitting.
• 📌 A hose clamp plier is a specialty plier that squeezes spring clamps evenly and makes them easier to move.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Let the Cooling System Cool

• Use your gloved hand to carefully feel near the upper radiator hose without squeezing it hard.
• If the hose or radiator area feels warm, wait longer.
• Once fully cool, slowly loosen the coolant reservoir cap by hand to release any leftover pressure.
• Cold engine only.

Step 2: Raise the Front if Replacing the Lower Hose

• If replacing only the upper hose, you usually do not need to raise your Highlander.
• If replacing the lower hose, use a floor jack rated 3-ton minimum at the front center jacking point.
• Place jack stands rated 3-ton minimum under the front support points.
• Gently lower your Highlander onto the jack stands and shake the vehicle lightly to confirm it is stable.

Step 3: Remove the Lower Engine Cover if Needed

• Use a 10mm socket, 3/8-inch ratchet, and 3/8-inch extension to remove the under cover bolts.
• Use a plastic trim clip remover to remove any plastic clips.
• Set the cover and fasteners aside in order.
• When reinstalling under cover bolts later, tighten them snugly by hand with the 10mm socket. Do not over-tighten plastic cover hardware.

Step 4: Position the Drain Pan

• Place the drain pan rated 2-gallon minimum under the radiator hose connection you are removing.
• For the upper hose, place the pan under the radiator’s upper hose area.
• For the lower hose, place the pan directly below the lower radiator hose connection.

Step 5: Drain Enough Coolant

• Use a flathead screwdriver 6-inch or your hand to open the radiator drain cock if accessible.
• Drain coolant until the level is below the hose you are replacing.
• If the drain cock is hard to access, leave it alone and expect coolant to drain when the hose is loosened.
• Close the radiator drain cock by hand once draining slows. Do not force it.

Step 6: Move the Hose Clamps Back

• Use hose clamp pliers or slip-joint pliers 10-inch to squeeze the spring clamp tabs together.
• Slide the clamp back several inches onto the hose.
• Repeat this on the other end of the hose.
• If screw-style clamps are installed, use a flathead screwdriver 6-inch to loosen them.
• Do not pry on plastic radiator necks.

Step 7: Remove the Old Radiator Hose

• Use your gloved hands to twist the hose gently to break it loose.
• If it is stuck, use a flathead screwdriver 6-inch very carefully between the hose and metal fitting only.
• Do not dig into the radiator neck. The radiator neck can crack if pried hard.
• Pull the hose off and let coolant drain into the pan.
• Remove the old clamps if you are installing new clamps.

Step 8: Clean the Hose Connections

• Use clean shop towels to wipe the radiator and engine hose fittings.
• Make sure no old rubber pieces remain stuck to the fittings.
• Check the radiator neck for cracks or heavy corrosion before installing the new hose.

Step 9: Install the New Hose

• Slide the new radiator hose clamps onto the new hose first.
• Push the new hose fully onto the radiator fitting by hand.
• Push the other end fully onto the engine fitting by hand.
• Use hose clamp pliers or slip-joint pliers 10-inch to move each clamp into position behind the raised bead on the fitting.
• If using screw-style clamps, tighten them evenly with a flathead screwdriver 6-inch until snug. Do not crush the hose.
• Clamp behind the raised bead.

Step 10: Refill the Cooling System

• Use a funnel with long neck at the coolant reservoir fill point.
• Add Toyota Super Long Life Coolant 50/50 premix until the reservoir reaches the FULL mark.
• If coolant was drained from the radiator and the radiator cap is accessible, fill the radiator first, then fill the reservoir.
• Install the cap by hand once the level is correct.

Step 11: Bleed Air from the Cooling System

• Start the engine and let it idle with the heater set to full hot and fan on low.
• Watch the temperature gauge. It should rise normally and stay near the middle.
• Let the engine idle until the radiator fans cycle on, if safe to do so.
• Shut the engine off and let it cool completely.
• Use the funnel with long neck to top off the coolant reservoir to the FULL mark after it cools.

Step 12: Reinstall the Lower Engine Cover

• Use the plastic trim clip remover to align any clips.
• Use the 10mm socket, 3/8-inch ratchet, and 3/8-inch extension to reinstall the under cover bolts.
• Tighten cover bolts snugly. Do not over-tighten plastic under cover fasteners.

Step 13: Lower the Vehicle

• Use the floor jack rated 3-ton minimum to lift your Highlander slightly off the jack stands.
• Remove the jack stands rated 3-ton minimum.
• Lower the vehicle slowly onto level ground.

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✅ After Repair

• ✅ Check for leaks at both ends of the replaced hose while the engine idles.
• ✅ After the first full heat-up and cool-down, recheck the coolant level and top off if needed.
• ✅ Take a short test drive while watching the temperature gauge.
• ✅ Recheck for drips under the front of your Highlander after parking.
• ✅ Dispose of old coolant at a proper recycling or hazardous-waste facility. Do not pour it on the ground or into drains.

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💰 DIY vs Shop Cost

Shop Cost: $180-$350 (parts + labor)

DIY Cost: $35-$120 (parts only)

You Save: $145-$230 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.8-1.5 hours.

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🎯 Ready to get started?

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