🔧 Highlander - Radiator Hose Replacement

This job replaces a leaking, swollen, cracked, or soft radiator hose on your Highlander. The radiator hoses carry hot engine coolant between the engine and radiator, so the engine must be completely cool before you start.

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

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⚠️ Safety & Precautions

• ⚠️ Never open the radiator cap when the engine is hot. Hot coolant can spray out and cause serious burns.
• 🧤 Wear gloves and safety glasses. Toyota Super Long Life Coolant is slippery and irritating to skin and eyes.
• 🐾 Keep coolant away from children and pets. It is toxic if swallowed.
• 🔋 Battery disconnect is not required for this repair.
• 🌡️ Let your Highlander sit until the upper radiator hose feels completely cool to the touch.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• Drain pan 2-gallon minimum
• Plastic funnel
• Hose clamp pliers
• Slip-joint pliers 10-inch
• Flat-blade screwdriver 6-inch
• Pick tool set
• 10mm socket
• 3/8-inch drive ratchet
• 3/8-inch drive extension 6-inch
• Coolant spill-free funnel kit (specialty)
• Clean shop towels

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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 if replacing lower hose
• Radiator hose clamps - Qty: 2 per hose if original clamps are weak, rusty, or damaged
• Toyota Super Long Life Coolant, pink, premixed 50/50 - Qty: 1-2 gallons

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📋 Before You Begin

• 🅿️ Park your Highlander on level ground and set the parking brake.
• ❄️ Make sure the engine is completely cold before removing the radiator cap or any hose.
• 🧴 A hose clamp is the spring or screw band that holds the hose tightly to the metal or plastic fitting.
• 🪛 A pick tool is a small hooked tool used to gently break the hose loose from the fitting without cutting it.
• 🚫 Do not mix green universal coolant with Toyota pink coolant unless the bottle clearly states Toyota Super Long Life compatibility.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Let the Engine Cool

• Use your gloved hand to touch the upper radiator hose. It must feel cool, not warm.
• Use safety glasses before opening the cooling system.
• Slowly remove the radiator cap by hand only after the engine is completely cold.
• Cold engine only.

Step 2: Remove the Front Lower Access Panel if Needed

• Use a 10mm socket, 3/8-inch drive ratchet, and 6-inch extension to remove any fasteners holding the lower splash shield if it blocks access to the radiator drain.
• Set the fasteners aside in order so they go back into the same locations.
• When reinstalling small 10mm splash shield bolts, snug them by hand with the ratchet. Do not overtighten plastic shield fasteners.

Step 3: Drain Some Coolant

• Place a 2-gallon drain pan under the radiator drain area.
• Use your hand or slip-joint pliers gently if needed to open the radiator drain cock at the lower radiator area.
• Drain enough coolant so the level drops below the hose you are replacing.
• For the upper hose, draining about 1 gallon is usually enough.
• For the lower hose, drain more coolant because the hose is near the bottom of the radiator.
• Close the radiator drain cock by hand until snug. Do not force it.

Step 4: Remove the Old Hose Clamps

• Use hose clamp pliers to squeeze the spring clamp tabs together.
• Slide the clamp back onto the hose, away from the radiator or engine fitting.
• If your Highlander has worm-gear replacement clamps, use a flat-blade screwdriver to loosen them.
• Repeat this on both ends of the hose.
• Take a photo first.

Step 5: Break the Hose Loose

• Use your hands to twist the hose gently back and forth.
• If it is stuck, use a pick tool carefully between the hose and fitting to break the seal.
• Do not pry hard against the radiator plastic neck. It can crack.
• Use slip-joint pliers only to twist the rubber hose gently, not to crush the radiator fitting.

Step 6: Remove the Old Hose

• Pull the hose straight off by hand once it is loose.
• Keep the drain pan under the hose because more coolant may spill out.
• Use clean shop towels to wipe spilled coolant from nearby parts.

Step 7: Inspect and Clean the Hose Fittings

• Use clean shop towels to wipe the radiator and engine hose fittings clean.
• Use a pick tool gently to remove stuck rubber pieces if the old hose left residue behind.
• Do not sand or scratch plastic radiator fittings.
• If a plastic radiator neck is cracked, the radiator must be replaced before installing the hose.

Step 8: Install the New Hose

• Compare the new hose to the old hose by hand. The bends and length should match.
• Slide the clamps onto the new hose before installing it.
• Push the new hose fully onto the radiator and engine fittings by hand until it seats past the raised bead on each fitting.
• A raised bead is the small lip near the end of the fitting that helps keep the hose from slipping off.
• Do not use oil or grease on the hose. If needed, use a tiny amount of clean Toyota coolant on the inside of the hose end.

Step 9: Position the Hose Clamps

• Use hose clamp pliers to move each spring clamp into its original position.
• Place each clamp behind the raised bead on the fitting, not on the very edge.
• If using screw-style hose clamps, tighten with a flat-blade screwdriver until snug. Do not crush the hose or plastic radiator neck.
• No torque spec is used for Toyota spring clamps; they lock by spring tension.

Step 10: Refill the Cooling System

• Install the coolant spill-free funnel kit onto the radiator filler neck.
• Use a plastic funnel to add Toyota Super Long Life Coolant, pink, premixed 50/50.
• Fill the radiator slowly until coolant stays near the top.
• Fill the coolant reservoir to the “FULL” line using the plastic funnel.

Step 11: Bleed Air from the Cooling System

• Leave the coolant spill-free funnel kit installed.
• Start the engine and set the heater to full hot with the blower on low.
• Let the engine idle while watching the coolant level in the funnel.
• Add coolant with the plastic funnel as the level drops.
• Gently squeeze the upper radiator hose by hand a few times to help move air bubbles out.
• When the radiator fans cycle on and warm air comes from the vents, most air is out.
• Shut the engine off and let it cool completely.

Step 12: Reinstall the Access Panel

• Use a 10mm socket, 3/8-inch drive ratchet, and 6-inch extension to reinstall the lower splash shield if removed.
• Tighten the fasteners snugly by hand. Do not overtighten plastic retainers or small shield bolts.

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✅ After Repair

• ✅ After the engine cools completely, recheck the radiator and coolant reservoir levels.
• 🔍 Inspect both ends of the new hose for leaks with the engine idling.
• 🌡️ Watch the temperature gauge during the first drive. It should stay in the normal range.
• 🚗 Take a short 10-minute test drive, then park and check again for drips.
• ♻️ Pour used coolant into a sealed container and recycle it properly. Do not dump it on the ground or into drains.

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💰 DIY vs Shop Cost

Shop Cost: $180-$350 per hose, or $300-$550 for upper and lower hoses together

DIY Cost: $35-$120 per hose, plus coolant if needed

You Save: $120-$350 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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