🔧 Highlander - Water Pump Replacement

The water pump circulates coolant through your engine and radiator. When it leaks or the bearing fails, you can get coolant loss, overheating, or a whining/grinding noise. On your Highlander’s V6, the water pump is driven by the serpentine belt, so you’ll remove the belt and unbolt the pump from the engine.

Difficulty Level: Advanced | Estimated Time: 3-6 hours

Assumption: V6 3.5L 2GR-family layout; verify torque specs with Toyota service data.

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⚠️ Safety & Precautions

• ⚠️ Work on a fully cold engine to avoid burns from hot coolant.
• ⚠️ Support the vehicle with jack stands; never rely on a floor jack alone.
• ⚠️ Coolant is toxic—use a drain pan and keep it away from kids/pets.
• ⚠️ Keep fingers/tools clear of belts and pulleys when checking operation.
• ⚠️ Battery disconnect is not strictly required, but disconnecting the negative terminal is safer when working near the belt and alternator area.

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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)
• Funnel
• Metric socket set (8mm–19mm)
• 10mm socket
• 12mm socket
• 14mm socket
• 3/8" drive ratchet
• 1/2" drive breaker bar
• Torque wrench (5–80 ft-lbs range)
• Serpentine belt tool (specialty)
• Flathead screwdriver
• Trim clip removal tool
• Pliers
• Razor scraper
• Plastic gasket scraper
• Shop rags
• Brake cleaner spray

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Water pump (V6 3.5L) - Qty: 1
• Water pump gasket / O-ring (as applicable) - Qty: 1
• Toyota Super Long Life Coolant (pink, premixed) - Qty: 2 gallons
• Serpentine belt - Qty: 1
• Replacement hose clamps (worm gear or OE-style) - Qty: 2

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📋 Before You Begin

• Park on level ground, set the parking brake, and chock the rear wheels.
• Let the engine cool completely (coolant system must be cold).
• Use a 10mm socket to disconnect the negative battery terminal and tuck it aside.
• Set your HVAC to heat later during bleeding (this opens the heater core so air can purge).

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Raise the front and remove the splash shielding

• Use a floor jack and jack stands to safely support the front of your Highlander.
• Use a trim clip removal tool and flathead screwdriver to remove the plastic clips/screws holding the lower engine cover and right-side splash shield.
• Keep clips grouped by panel.

Step 2: Drain the coolant

• Place a drain pan under the radiator drain (petcock).
• Slowly remove the radiator cap to release any residual pressure.
• Open the radiator drain and let coolant drain fully into the pan.
• Use pliers to release any lower splash-area hose clamps only if you need extra clearance.

Step 3: Remove the serpentine belt

• Locate the belt tensioner (spring-loaded pulley that keeps the belt tight).
• Use a serpentine belt tool or breaker bar to rotate the tensioner and relieve belt tension, then slip the belt off the pulleys.
• Take a quick photo of belt routing.

Step 4: Create access to the water pump area

• Use a 10mm socket and 12mm socket to remove any brackets, wire looms, or covers blocking the water pump.
• If a hose is attached at the pump area, use pliers to move the clamp back and carefully twist the hose free.
• Twist hoses gently; don’t pry hard.

Step 5: Remove the water pump

• Place shop rags below the pump area; more coolant will spill.
• Use a 10mm socket and 12mm socket to remove the water pump mounting bolts.
• Remove the pump from the engine. If it’s stuck, tap lightly by hand and wiggle it free—do not hammer on the aluminum engine.
• Remove the old gasket/O-ring.

Step 6: Clean the sealing surface

• Use a plastic gasket scraper to remove any old gasket material without gouging the aluminum surface.
• Use brake cleaner spray and shop rags to wipe the mating surface until clean and dry.
• Clean, flat surfaces prevent future leaks.

Step 7: Install the new water pump

• Install the new gasket/O-ring onto the new pump (match the original position exactly).
• Position the pump on the engine and hand-thread all bolts first to avoid cross-threading.
• Use a torque wrench to tighten bolts evenly in a crisscross pattern. Torque to Toyota specification for your exact bolt sizes.

Step 8: Reinstall brackets/hoses and the serpentine belt

• Reinstall any brackets/covers you removed using a 10mm socket and 12mm socket. Torque to Toyota specification.
• Reattach hoses and position clamps using pliers.
• Route the serpentine belt correctly, then use the serpentine belt tool to rotate the tensioner and slip the belt back on.
• Visually confirm the belt is seated in every pulley groove.

Step 9: Refill and bleed the cooling system

• Close the radiator drain.
• Use a funnel to fill with Toyota Super Long Life Coolant (pink, premixed) until full.
• Reconnect the negative battery terminal using a 10mm socket.
• Start the engine and set HVAC to the hottest setting with the fan on low.
• Let it idle and watch the coolant level; add coolant as the level drops.
• Continue until heat blows hot and the engine reaches normal temperature. Shut off, let cool, then top off again.

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✅ After Repair

• Check carefully for leaks around the water pump and hose connections while idling.
• Test drive 10–15 minutes, then recheck for leaks and recheck coolant level after a full cool-down.
• Verify the temperature gauge stays normal and cabin heat works (no heat can mean trapped air).
• Dispose of old coolant properly (many parts stores accept waste fluids).

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💰 DIY vs Shop Cost

Shop Cost: $700-$1,300 (parts + labor)

DIY Cost: $180-$450 (parts only)

You Save: $520-$850 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 3-6 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.