🔧 Highlander - Radiator Hose Replacement

A radiator hose carries coolant between the radiator and the engine. Replacing a cracked, swollen, leaking, or oil-soaked hose helps prevent overheating and coolant loss.

Difficulty Level: Intermediate | Estimated Time: 1.0-2.5 hours

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⚠️ Safety & Precautions

• ⚠️ Never open the cooling system hot; let your Highlander cool completely.
• ⚠️ Coolant is toxic; keep it off skin/eyes and away from pets.
• ⚠️ Support the vehicle with jack stands before working underneath.
• ⚠️ Keep hands/tools clear of the radiator fan; it can turn on automatically.
• 🔋 Battery disconnect is not required for hose replacement, but keep the key away from the vehicle while working near the fan.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• Drain pan (at least 10-quart)
• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks
• 10mm socket
• 12mm socket
• 3/8" ratchet
• 6" extension
• Flathead screwdriver
• Hose clamp pliers (specialty)
• Pick tool (specialty)
• Razor scraper (plastic)
• Funnel
• Spill-free coolant funnel kit (specialty)
• Shop towels
• Torque wrench (10–80 Nm range)

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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: 2-4
• Toyota Super Long Life Coolant (pink) 50/50 premix - Qty: 1-2 gallons

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📋 Before You Begin

• Park on level ground, set the parking brake, and install wheel chocks.
• Let the engine cool until the upper radiator hose is cool to the touch.
• Place a drain pan under the radiator area to catch coolant.
• If you’re doing the lower hose, raise the front using a floor jack and support with jack stands.
• Hose clamp pliers squeeze spring clamps safely.
• A pick tool helps break a stuck hose seal.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the front lower cover (if needed for access)

• If the hose connection is blocked, remove the lower engine splash shield using a 10mm socket, 12mm socket, and 3/8" ratchet.
• Keep bolts/clips organized for reassembly.

Step 2: Relieve pressure safely

• With the engine fully cool, slowly loosen the coolant cap (radiator cap or reservoir cap) by hand and stop if you hear pressure release.
• Once pressure is fully released, remove the cap completely.

Step 3: Drain enough coolant to get below the hose level

• Position the drain pan under the radiator.
• If your radiator has a drain cock, open it carefully by hand or with a flathead screwdriver if needed (do not force it).
• If you can’t access the drain cock, you can drain from the lower hose in Step 5—expect more spillage.

Step 4: Identify which hose you’re replacing (Upper vs Lower)

• Upper radiator hose: runs from the top of the radiator to the engine.
• Lower radiator hose: runs from the bottom of the radiator down to the engine area; usually needs access from below.

Step 5: Remove the hose clamps

• If you have spring clamps, squeeze the tabs using hose clamp pliers (specialty) and slide the clamp back on the hose.
• If you have screw clamps, loosen them using a flathead screwdriver.
• Repeat for the clamp on the other end of the hose.

Step 6: Break the hose free and remove it

• Twist the hose by hand to break the seal.
• If it’s stuck, carefully work around the hose end with a pick tool (specialty) to release it. Do not gouge the plastic/metal fitting.
• Pull the hose off and let coolant drain into the drain pan.

Step 7: Clean the fittings

• Use shop towels to wipe the hose connection surfaces.
• If there’s buildup, gently clean with a plastic razor scraper.
• Do not use heavy abrasives; you want the sealing surface smooth.

Step 8: Install the new hose and position clamps

• Match the new hose shape to the old hose before installing.
• Push the hose fully onto each fitting until it bottoms out.
• Reposition clamps using hose clamp pliers (specialty) or tighten screw clamps using a flathead screwdriver.
• Place the clamp behind the raised bead on the fitting (this helps prevent leaks).

Step 9: Reinstall the lower cover (if removed)

• Reinstall the splash shield using a 10mm socket, 12mm socket, and 3/8" ratchet.
• If any fasteners are bolts, use a torque wrench and Torque to 7–9 Nm (62–80 in-lbs) unless the fastener is clearly a larger structural bolt.

Step 10: Refill coolant and bleed air

• Refill using a funnel or spill-free coolant funnel kit (specialty) with Toyota Super Long Life Coolant (pink) 50/50 premix.
• Set the cabin heat to MAX HOT and the fan to LOW.
• Start the engine and let it idle while watching the coolant level.
• As the engine warms, gently squeeze the upper hose a few times to help move trapped air (use gloves).
• When the level stabilizes and warm air blows from the vents, shut the engine off and let it cool fully, then recheck and top off.

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✅ After Repair

• With the engine running, inspect both hose ends for seepage.
• Bring the engine up to normal operating temperature and verify the heater is hot.
• After a full cool-down, recheck the coolant level and top off as needed.
• Over the next 2-3 drives, recheck for leaks and watch the temperature gauge.

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💰 DIY vs Shop Cost

Shop Cost: $250-$550 (parts + labor)

DIY Cost: $60-$180 (parts only)

You Save: $190-$370 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.0-2.0 hours.

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🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.