🔧 Highlander - Water Pump Replacement

You’ll be removing the old engine water pump on your Highlander and installing a new one, then refilling and bleeding the cooling system. This restores proper coolant circulation and prevents overheating or coolant leaks.

Difficulty Level: Intermediate | Estimated Time: 3-5 hours

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⚠️ Safety & Precautions

• ⚠️ Only work on a cold engine. Hot coolant can cause serious burns.
• ⚠️ Support the vehicle with jack stands if you lift it; never rely on a jack alone.
• ⚠️ Coolant is toxic. Avoid skin contact and keep away from children/pets.
• ⚠️ Disconnect the negative battery cable before starting to avoid accidental electrical shorts.
• ⚠️ Properly dispose of old coolant at a recycling center; do not pour on the ground or into drains.
• ⚠️ Keep tools and loose clothing away from the belt and pulleys when rotating the engine by hand.

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🔧 Required Tools

You'll need the following tools for this repair:

• 🛠️ Floor jack (rated 3-ton minimum)
• 🛠️ Jack stands (rated 3-ton minimum, set of 2)
• 🛠️ Wheel chocks
• 🛠️ 10mm socket
• 🛠️ 12mm socket
• 🛠️ 14mm socket
• 🛠️ 3/8" drive ratchet
• 🛠️ 1/2" drive ratchet
• 🛠️ Short 3/8" drive extension (2"-3")
• 🛠️ Long 3/8" drive extension (6")
• 🛠️ Serpentine belt tool or long-handled 14mm wrench (specialty)
• 🛠️ Torque wrench (3/8" drive, 5-80 Nm range)
• 🛠️ Torque wrench (1/2" drive, 20-150 Nm range)
• 🛠️ Flathead screwdriver (medium)
• 🛠️ Phillips screwdriver (medium)
• 🛠️ Pliers (standard)
• 🛠️ Hose clamp pliers (specialty)
• 🛠️ Plastic trim clip removal tool (specialty)
• 🛠️ Plastic scraper
• 🛠️ Drain pan (at least 10 liters capacity)
• 🛠️ Shop rags
• 🛠️ Funnel with small spout
• 🛠️ Coolant funnel / spill-free funnel kit (specialty)
• 🛠️ Safety glasses
• 🛠️ Mechanic gloves
• 🛠️ Work light or LED lamp

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• 🔩 Engine water pump assembly (with gasket or O-ring) - Qty: 1
• 🔩 Serpentine drive belt - Qty: 1
• 🔩 Toyota Super Long Life coolant (pink, premixed 50/50) - Qty: 8-10 liters
• 🔩 Thermostat with gasket - Qty: 1 (recommended while coolant is drained)
• 🔩 New hose clamps (assorted sizes for coolant hoses) - Qty: 4-6 (as needed)
• 🔩 RTV silicone sealant (coolant-safe) - Qty: 1 small tube (only if specified with your pump)
• 🔩 Plastic clips for lower engine cover / splash shield - Qty: 4-8 (in case some break)
• 🔩 Brake cleaner or engine-safe cleaner spray - Qty: 1
• 🔩 Distilled water - Qty: 2 liters (for rinsing small spills, not for mixing with premix)

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📋 Before You Begin

• Park the Highlander on level ground, set the parking brake, and place wheel chocks behind the rear wheels.
• Let the engine cool fully (at least 1-2 hours after last running).
• Open the hood and remove any loose items from the engine bay area.
• Disconnect the negative battery cable using a 10mm socket and move it aside so it cannot touch the terminal.
• Have your drain pan, rags, and new coolant ready before loosening anything related to coolant.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Raise the front and remove the lower engine cover

• Use the floor jack to lift the front of the Highlander at the front jacking point.
• Place the vehicle securely on jack stands under the approved pinch weld or frame points.
• Use a plastic trim clip removal tool and 10mm socket to remove the clips and bolts holding the lower engine cover / splash shield.
• Remove the cover and set the clips and bolts aside in a tray.

Step 2: Drain the engine coolant

• Position the drain pan under the radiator drain cock or lower radiator hose.
• Use a flathead screwdriver or your hand (depending on style) to open the radiator drain cock slightly, or use hose clamp pliers to loosen the clamp on the lower radiator hose and carefully pull the hose off.
• Remove the coolant reservoir cap and radiator cap (if equipped) to allow coolant to flow freely.
• Allow coolant to finish draining, then close the drain cock or reinstall the lower radiator hose and tighten the clamp with pliers.
• Keep drain pan stable to avoid spills

Step 3: Remove engine covers and intake ducting for access

• Use a 10mm socket to remove any bolts holding the plastic engine cover, then lift the cover off.
• Use a flathead screwdriver to loosen the clamps on the intake air duct between the air box and throttle body.
• Disconnect any small hoses or connectors in the way by hand or with pliers if needed.
• Remove the intake duct and set aside for more room near the front of the engine.

Step 4: Remove the serpentine drive belt

• Note the belt routing; take a clear photo or sketch it. There is usually a routing diagram under the hood.
• Locate the belt tensioner (a pulley on a spring-loaded arm).
• Use a serpentine belt tool or long-handled 14mm wrench on the tensioner bolt to rotate the tensioner and relieve belt tension.
• While holding the tensioner, slide the belt off one pulley by hand, then slowly release the tensioner back to its resting position.
• Remove the belt completely from all pulleys and set it aside (replace with new).

Step 5: Remove components blocking access to the water pump

• The water pump on the 3.5L V6 is mounted at the front of the engine and driven by the belt.
• Use a 12mm socket and ratchet to remove any brackets or idler pulleys that block access to the pump and its bolts.
• Keep bolts organized and note where each came from.
• Take photos before removing brackets

Step 6: Remove the water pump pulley (if separate)

• If your pump has a separate pulley bolted to it, secure the pulley from turning by holding it with a strap or carefully with pliers on the outer edge.
• Use a 12mm socket to loosen and remove the water pump pulley bolts.
• Remove the pulley and set it aside.

Step 7: Remove the water pump

• Place the drain pan directly under the water pump area because more coolant will spill when the pump comes off.
• Use a 10mm socket and 3/8" ratchet with extensions as needed to remove all water pump mounting bolts.
• There are several bolts around the pump; note their different lengths and positions.
• Gently tap the pump with the palm of your hand or a soft mallet to break it loose; do NOT pry hard against the engine block.
• Pull the pump straight off the engine. Allow coolant to drain fully.
• Do not drop bolts into the engine bay

Step 8: Clean the mounting surface

• Use a plastic scraper to carefully remove old gasket material from the engine’s water pump mounting surface.
• Do not use metal tools that can scratch the aluminum surface.
• Wipe the surface clean with shop rags and a small amount of brake cleaner or engine-safe cleaner.
• Ensure the surface is smooth, clean, and dry before installing the new pump.

Step 9: Prepare the new water pump

• Install the new gasket or O-ring onto the new pump as directed by the pump instructions.
• If the service info or pump instructions specify, apply a thin bead of RTV silicone sealant only where indicated (many pumps use a dry gasket and no RTV).
• Do not overuse sealant; thin bead only

Step 10: Install the new water pump

• Position the new pump against the engine, aligning the bolt holes and dowel pins if present.
• Hand-thread all the water pump bolts using your fingers to avoid cross-threading.
• Use a 10mm socket and 3/8" ratchet to snug each bolt in a crisscross pattern.
• Then use a torque wrench (3/8" drive) with a 10mm socket to tighten the bolts to 9 Nm (80 in-lbs) in a crisscross pattern.
• Wipe any excess sealant that squeezes out around the edges.

Step 11: Reinstall the water pump pulley and brackets

• Install the water pump pulley back onto the pump hub.
• Hand-thread the pulley bolts, then hold the pulley and tighten the bolts with a 12mm socket.
• Use a torque wrench and 12mm socket to torque the pulley bolts to 19 Nm (14 ft-lbs).
• Reinstall any brackets or idler pulleys you removed earlier using the 12mm or 14mm socket as appropriate.
• Tighten bracket and idler bolts to approximately 34 Nm (25 ft-lbs) with the torque wrench, unless otherwise specified for the particular bracket.

Step 12: Install the new serpentine belt

• Route the new belt according to the factory belt routing diagram or your photo/sketch.
• Leave the belt off one easy-to-reach pulley (usually an idler) for last.
• Use the serpentine belt tool or 14mm wrench to rotate the tensioner again and slip the belt fully onto the last pulley.
• Slowly release the tensioner, allowing it to tension the belt.
• Check that the belt is seated correctly in all pulley grooves.

Step 13: Reinstall intake ducting and engine cover

• Reinstall the intake air duct and reconnect any hoses or connectors you removed, tightening clamps with the flathead screwdriver.
• Reinstall the plastic engine cover and tighten its bolts with a 10mm socket.

Step 14: Reinstall the lower engine cover and lower the vehicle

• Reinstall the lower engine cover / splash shield using the original clips and bolts with the plastic trim clip tool and 10mm socket.
• Use the floor jack to lift slightly, remove the jack stands, and lower the vehicle back to the ground.

Step 15: Refill the cooling system

• Make sure the radiator drain cock and all hoses are securely closed.
• Install a coolant funnel / spill-free funnel at the radiator neck or reservoir (depending on your setup).
• Slowly pour Toyota Super Long Life pink coolant into the funnel until it reaches the “FULL” level in the reservoir and the radiator is full.
• Squeeze the upper radiator hose gently by hand to help push out trapped air.

Step 16: Bleed the cooling system and check for leaks

• Reconnect the negative battery cable using a 10mm socket.
• Start the engine and let it idle with the heater set to maximum heat and fan on medium.
• Watch the coolant level in the funnel and add coolant as it drops.
• Let the engine reach normal operating temperature; the radiator fans should cycle on and off.
• Watch for steady heat from the vents (this shows coolant is circulating).
• Check under the vehicle and around the water pump area for leaks using a work light.
• Once air bubbles stop coming up and the level stabilizes, shut off the engine and let it cool.
• After it cools completely, recheck and top off the coolant in the reservoir to the “FULL” mark.

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✅ After Repair

• Check for any coolant drips under the Highlander after your first drive.
• The next morning (engine cold), recheck the coolant level and top off the reservoir if needed.
• Listen for abnormal noises from the belt or water pump area; a chirp or squeal may indicate belt misalignment.
• Watch the temperature gauge for several days to ensure the engine does not overheat.
• Properly dispose of the old coolant at a recycling center or service shop.

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💰 DIY vs Shop Cost

Shop Cost: $650-$1,000 (parts + labor)

DIY Cost: $200-$350 (parts only)

You Save: $450-$650 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 3-4 hours.

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🎯 Ready to get started?

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