🔧 Highlander - Engine Water Pump Replacement

This guide covers replacing the engine coolant water pump on your Highlander. The water pump circulates coolant through the V6 engine, and a failing pump can cause coolant leaks, bearing noise, or overheating.

Difficulty Level: Advanced | Estimated Time: 4-6 hours

Assumption: This is for the engine mechanical water pump, not the hybrid inverter electric coolant pump.

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⚠️ Safety & Precautions

• ⚠️ Your Highlander is a hybrid. Do not touch orange high-voltage cables or hybrid system components.
• ⚠️ Let the engine cool completely before opening the cooling system. Hot coolant can cause serious burns.
• ⚠️ Disconnect the 12-volt battery negative cable before working near the engine accessory drive area.
• ⚠️ Support the engine correctly before removing any engine mount bracket. An engine support bar holds the engine from above so it cannot drop.
• ⚠️ Use only Toyota-compatible coolant. Mixing the wrong coolant can damage the cooling system.
• ⚠️ Keep coolant away from pets and children. It is poisonous.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 12mm socket
• 14mm socket
• 17mm socket
• 19mm socket
• 3/8-inch drive ratchet
• 1/2-inch drive ratchet
• 3/8-inch drive extension set
• 1/2-inch drive breaker bar
• Torque wrench 5-80 ft-lbs
• Serpentine belt tool 14mm
• Flat-blade screwdriver
• Trim clip removal tool
• Pliers
• Plastic gasket scraper
• Drain pan 2-gallon minimum
• Funnel
• Cooling system vacuum fill tool (specialty)
• Engine support bar (specialty)
• Floor jack rated 3-ton minimum
• Jack stands rated 3-ton minimum
• Wheel chocks
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Engine water pump - Qty: 1
• Water pump gasket - Qty: 1
• Toyota Super Long Life Coolant premixed 50/50 - Qty: 2 gallons
• Serpentine belt - Qty: 1
• Engine mount bracket bolts - Qty: as needed if damaged or corroded
• Coolant drain plug gasket - Qty: 1

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📋 Before You Begin

• 🅿️ Park your Highlander on level ground, shift to Park, and set the parking brake.
• 🧊 Let the engine sit until it is fully cool.
• 🔋 Disconnect the 12-volt battery negative cable using a 10mm socket.
• 🚗 Place wheel chocks behind the rear wheels before lifting the front.
• 🛠️ A serpentine belt is the long rubber belt that turns accessories on the front of the engine.
• 🛠️ A torque wrench tightens bolts to the correct tightness so parts are not damaged.
• 🛠️ A vacuum fill tool removes air while refilling coolant. It helps prevent overheating caused by trapped air.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Raise and Support the Front

• Use a floor jack rated 3-ton minimum to lift the front of your Highlander at the front center jacking point.
• Place jack stands rated 3-ton minimum under the front support points.
• Gently lower the vehicle onto the stands and shake the vehicle lightly to confirm it is stable.
• Wear safety glasses and nitrile gloves.

Step 2: Remove the Lower Engine Covers

• Use a 10mm socket to remove the lower splash shield bolts.
• Use a trim clip removal tool to remove plastic clips without breaking them.
• Set the covers and clips aside in order.
• Take photos before disassembly.

Step 3: Drain the Engine Coolant

• Place a drain pan 2-gallon minimum under the radiator drain area.
• Slowly loosen the radiator cap only after the engine is completely cool.
• Use pliers or your fingers, depending on access, to open the radiator drain cock.
• Allow the coolant to drain fully into the pan.
• Close the radiator drain cock by hand until snug. Do not overtighten plastic drain parts.

Step 4: Remove the Right Front Wheel and Fender Liner Access

• Use a 21mm socket if available, or the vehicle lug wrench, to loosen the right front wheel lug nuts before fully lifting if not already lifted.
• Remove the right front wheel.
• Use a 10mm socket and trim clip removal tool to loosen the right front inner fender liner for side access.
• When reinstalling the wheel later, tighten lug nuts to Torque to 103 Nm (76 ft-lbs).

Step 5: Remove the Serpentine Belt

• Use a serpentine belt tool 14mm on the belt tensioner.
• Rotate the tensioner slowly to release belt tension.
• Slide the belt off the pulleys and remove it.
• Draw or photograph the belt routing before removal.
• Slowly release the tensioner.

Step 6: Support the Engine

• Install an engine support bar across the upper body support points.
• Attach the support chain to the engine lifting point.
• Apply light upward tension only. Do not lift the engine high.
• If using a jack for light backup support, place a wood block between the jack and oil pan. Do not crush the pan.

Step 7: Remove the Right Engine Mount Bracket for Access

• Use a 14mm socket and 17mm socket to remove the right-side engine mount and bracket fasteners as needed for water pump access.
• Use a 3/8-inch drive extension set to reach recessed bolts.
• Keep each bolt grouped by location.
• During installation, tighten typical engine mount bracket bolts to Torque to 64 Nm (47 ft-lbs) unless your replacement mount instructions specify otherwise.

Step 8: Remove the Water Pump Pulley

• Use a 10mm socket to loosen the water pump pulley bolts.
• If the pulley spins, hold it carefully by hand with gloves while loosening the bolts.
• Remove the pulley and set it aside.
• On installation, tighten the pulley bolts evenly to Torque to 21 Nm (15 ft-lbs).

Step 9: Remove the Old Water Pump

• Use a 10mm socket and 12mm socket to remove the water pump mounting bolts.
• Note bolt lengths and locations. Some bolts may be different lengths.
• Gently separate the pump from the engine using a plastic gasket scraper.
• Do not gouge the aluminum engine surface.
• Remove the old gasket.

Step 10: Clean the Sealing Surface

• Use a plastic gasket scraper to clean the engine-side sealing surface.
• Use a clean rag to wipe the area dry.
• Do not use metal scrapers or power sanding discs.
• Clean surfaces prevent leaks.

Step 11: Install the New Water Pump

• Place the new water pump gasket on the new engine water pump.
• Position the pump squarely against the engine.
• Start all bolts by hand first to avoid cross-threading.
• Use a 10mm socket and 12mm socket to snug the bolts evenly in a crisscross pattern.
• Tighten water pump bolts to Torque to 21 Nm (15 ft-lbs).

Step 12: Reinstall the Pulley, Mount Bracket, and Belt

• Use a 10mm socket to reinstall the water pump pulley.
• Tighten pulley bolts to Torque to 21 Nm (15 ft-lbs).
• Use a 14mm socket and 17mm socket to reinstall the engine mount bracket and mount fasteners.
• Tighten mount bracket fasteners to Torque to 64 Nm (47 ft-lbs).
• Use the serpentine belt tool 14mm to rotate the tensioner and install the new serpentine belt.
• Confirm the belt ribs sit correctly in every pulley groove.

Step 13: Refill the Cooling System

• Use a cooling system vacuum fill tool and funnel to refill with Toyota Super Long Life Coolant premixed 50/50.
• If filling without a vacuum tool, pour coolant slowly through a funnel into the radiator until full.
• Fill the coolant reservoir to the Full line.
• Leave the radiator cap off for the first bleed step.

Step 14: Reconnect the Battery and Bleed Air

• Use a 10mm socket to reconnect the 12-volt battery negative cable.
• Start the engine and set cabin heat to maximum temperature with low fan speed.
• Let the engine idle while watching the coolant level.
• Add coolant as the level drops.
• When no more bubbles appear and warm air comes from the vents, install the radiator cap.
• Watch the temperature gauge closely. Shut the engine off if it begins to overheat.

Step 15: Reinstall Covers and Wheel

• Use a 10mm socket and trim clip removal tool to reinstall the fender liner and lower splash shields.
• Reinstall the right front wheel.
• Use a torque wrench 5-80 ft-lbs if it covers the range, or a suitable higher-range torque wrench, to tighten lug nuts to Torque to 103 Nm (76 ft-lbs).
• Lower the vehicle with the floor jack rated 3-ton minimum.

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✅ After Repair

• ✅ Let the engine reach normal operating temperature while checking for leaks around the water pump.
• ✅ Test drive gently for 10-15 minutes while watching the temperature gauge.
• ✅ After the engine cools fully, recheck the radiator and reservoir levels. Top off with Toyota-compatible coolant if needed.
• ✅ Recheck under the vehicle for coolant drips after the first drive.
• ✅ If the heater blows cold at idle or the temperature rises, air may still be trapped in the system.
• ✅ Dispose of used coolant at a recycling or hazardous waste facility. Do not pour it on the ground.

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💰 DIY vs Shop Cost

Shop Cost: $650-$1,100 (parts + labor)

DIY Cost: $120-$300 (parts only)

You Save: $350-$800 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 3.5-5.0 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.