🔧 Highlander - Water Pump Replacement

On your Highlander’s 3.5L V6, the water pump circulates coolant through the engine and radiator. When it leaks or the bearing wears out, you’ll often see coolant dripping on the passenger side of the engine and/or hear grinding/whining. Replacing the pump stops the leak and prevents overheating.

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

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⚠️ Safety & Precautions

• ⚠️ Never open the cooling system hot; let it cool fully.
• ⚠️ Support the SUV with jack stands; never rely on a jack.
• ⚠️ Keep hands/tools clear of the serpentine belt path.
• ⚠️ If the radiator fans run unexpectedly, they can injure you—disconnecting the battery is safest.
• ⚠️ Coolant is toxic; use a drain pan and clean spills immediately.

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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)
• Wheel chocks
• Safety glasses
• Nitrile gloves
• Drain pan (at least 10-quart)
• 3/8" drive ratchet
• 3/8" drive torque wrench (10-80 ft-lbs)
• 1/4" drive torque wrench (inch-lb range)
• 3/8" drive extension set (3", 6")
• 10mm socket
• 12mm socket
• 14mm socket
• 14mm box wrench
• Flat-blade screwdriver
• Trim clip removal tool
• Pliers
• Plastic gasket scraper
• Shop towels
• Funnel

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Water pump assembly (with seal/gasket as supplied) - Qty: 1
• Toyota Super Long Life Coolant (pink, premixed 50/50) - Qty: 2-3 gallons
• Serpentine drive belt - Qty: 1 (recommended if worn/cracked)

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📋 Before You Begin

• Park on a level surface, set the parking brake, and chock the rear wheels.
• Let the engine cool completely (upper radiator hose should feel cool).
• Disconnect the negative battery cable using a 10mm socket.
• Plan to capture coolant in a drain pan for proper disposal.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Raise the front and remove the passenger-side wheel

• Use a floor jack (rated 3-ton minimum) to lift the front right, then support with jack stands (rated 3-ton minimum).
• Remove the passenger-side front wheel using a 21mm lug socket and breaker bar.

Step 2: Remove the right-side splash shield / fender liner

• Remove clips and screws using a trim clip removal tool and flat-blade screwdriver.
• Pull the liner back to access the belt and water pump area.

Step 3: Drain the coolant

• Place a drain pan (at least 10-quart) under the radiator drain.
• Open the radiator drain cock using pliers (turn slowly) and let coolant drain.
• Open the coolant reservoir cap to help it drain faster.

Step 4: Remove the serpentine belt

• Locate the belt tensioner (the spring-loaded arm that keeps the belt tight).
• Rotate the tensioner using a 14mm box wrench to relieve belt tension, then slide the belt off a pulley.
• Tip: Snap a photo of belt routing.

Step 5: Remove components blocking the water pump (as needed)

• If access is tight, remove small brackets/guards in the area using a 10mm socket and 12mm socket.
• Keep bolts organized in order of removal using labeled cups or bags.

Step 6: Remove the water pump

• Place shop towels under the pump area to catch remaining coolant.
• Remove the water pump mounting bolts using a 10mm socket with a 3/8" drive ratchet and extensions.
• Gently wiggle the pump free and remove it. More coolant will spill—catch it with the drain pan.

Step 7: Clean the mounting surface

• Clean the engine-side sealing surface using a plastic gasket scraper and shop towels.
• Do not gouge the aluminum surface. No old seal material should remain.

Step 8: Install the new water pump

• Confirm the new pump seal/gasket is correctly positioned.
• Install the pump and hand-start all bolts to avoid cross-threading.
• Tighten evenly in a crisscross pattern using a 10mm socket.
• Torque to 10 N·m (89 in-lbs) using a 1/4" drive torque wrench (inch-lb range).

Step 9: Reinstall the serpentine belt and shields

• Route the belt correctly, then rotate the tensioner with a 14mm box wrench and slip the belt on.
• Visually confirm the belt is centered on every pulley.
• Reinstall the splash shield using the trim clip removal tool and flat-blade screwdriver.
• Reinstall the wheel and snug lug nuts.

Step 10: Refill and bleed the cooling system

• Lower the SUV from the jack stands using the floor jack.
• Reconnect the battery negative cable using a 10mm socket.
• Refill with Toyota Super Long Life Coolant (pink, premixed 50/50) using a funnel.
• Start the engine and set the heater to HOT with the fan on low.
• Let it idle and watch the coolant level; top off as air purges.
• When warm, verify heat from vents and check for leaks at the pump.

Step 11: Final wheel torque

• Torque the lug nuts in a star pattern using a 3/8" drive torque wrench (10-80 ft-lbs).
• Torque to 103 N·m (76 ft-lbs).

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✅ After Repair

• Check for leaks with the engine running and again after a short drive.
• After the engine fully cools, recheck the radiator level and reservoir and top off as needed.
• Watch the temperature gauge on the first few drives; shut down if it overheats.

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💰 DIY vs Shop Cost

Shop Cost: $800-$1,400 (parts + labor)

DIY Cost: $180-$420 (parts only)

You Save: $620-$980 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 3-5 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.