🔧 BRZ - Water Pump Replacement

Your BRZ’s water pump circulates coolant through the engine and radiator. Replacing it involves draining coolant, removing the accessory drive belt, swapping the pump and gasket, then refilling and bleeding the cooling system to prevent overheating.

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

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⚠️ Safety & Precautions

• ⚠️ Work on a fully cold engine; hot coolant can cause severe burns.
• ⚠️ Support the car with jack stands; never rely on a floor jack alone.
• ⚠️ Keep coolant away from pets and kids; it’s toxic and attracts animals.
• ⚠️ Don’t let coolant spill onto the serpentine belt or electrical connectors.
• ⚠️ Battery disconnect is not required, but keep hands clear of the radiator fans (they can turn on unexpectedly).

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🔧 Required Tools

You'll need the following tools for this repair:

• Floor jack (rated 2-ton minimum)
• Jack stands (rated 2-ton minimum)
• Wheel chocks
• Safety glasses
• Nitrile gloves
• Drain pan (at least 10-quart)
• Funnel
• Spill-free coolant funnel kit (specialty)
• 3/8" drive ratchet
• 3/8" drive torque wrench
• 10mm socket
• 12mm socket
• 14mm socket
• 6" extension (3/8" drive)
• Flathead screwdriver
• Pliers (hose clamp pliers)
• Trim clip removal tool
• Plastic gasket scraper
• Shop towels

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Water pump - Qty: 1
• Water pump gasket / O-ring (as applicable) - Qty: 1
• Subaru-approved coolant (blue Super Coolant equivalent, premixed) - Qty: 2 gallons
• Accessory drive belt (serpentine belt) - Qty: 1

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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 (ideally overnight).
• Raise the front of the car with a floor jack and support it on jack stands at the factory jack points.
• Place a drain pan under the radiator area before opening any drain.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the front undercovers

• Use a floor jack and jack stands to safely support the front of the car.
• Use a trim clip removal tool and 10mm socket to remove the plastic clips and bolts holding the front undertray/splash shield.
• Set the undertray hardware aside in a small container. Mixing bolts is a common beginner mistake.

Step 2: Drain the coolant

• Position a drain pan (at least 10-quart) under the radiator drain area.
• Slowly loosen the radiator cap to relieve any leftover pressure (engine must be cold).
• Open the radiator drain using a flathead screwdriver (if your drain uses a screwdriver-style valve), and let coolant drain completely.
• Close the drain once finished (snug only—do not overtighten).

Step 3: Remove the accessory drive belt (serpentine belt)

• Locate the belt tensioner at the front of the engine.
• Use a 14mm socket and 3/8" drive ratchet to rotate the tensioner and relieve belt tension.
• Slide the belt off one pulley, then release the tensioner slowly and remove the belt completely.
• If you’re reusing the belt, take a photo of the routing before removal.

Step 4: Remove hoses and any components blocking the water pump

• Place shop towels under the pump area to catch remaining coolant.
• Use pliers (hose clamp pliers) to move spring clamps back, then twist and pull hoses off gently.
• If a hose is stuck, use a flathead screwdriver carefully to break the seal (do not gouge the plastic/metal fitting).

Step 5: Remove the water pump

• Remove water pump mounting bolts using a 10mm socket or 12mm socket (bolt heads can vary by location).
• Use a 6" extension (3/8" drive) where access is tight.
• Pull the water pump straight off the engine. Expect more coolant to spill—keep the drain pan under it.
• Remove the old gasket/O-ring and discard it.

Step 6: Clean the sealing surface

• Use a plastic gasket scraper to clean the engine’s water pump mating surface.
• Wipe clean with shop towels until the surface is smooth and dry.
• Do not use aggressive metal scrapers that can scratch aluminum and cause leaks.

Step 7: Install the new water pump and gasket/O-ring

• Install the new gasket/O-ring onto the new pump (match orientation exactly).
• Position the pump onto the engine and hand-thread all bolts first to avoid cross-threading.
• Tighten bolts evenly in a crisscross pattern using a 10mm socket/12mm socket and 3/8" drive ratchet.
• Final tighten using a 3/8" drive torque wrench to the Subaru spec for your pump fasteners: Torque to the OEM specification for your BRZ water pump bolts.

Step 8: Reinstall hoses and clamps

• Reinstall coolant hoses fully seated on their fittings.
• Use pliers (hose clamp pliers) to return spring clamps to their original positions.
• Wipe the area with shop towels so you can easily spot any new leaks later.

Step 9: Reinstall the accessory drive belt

• Route the belt around the pulleys exactly as it was.
• Use a 14mm socket and 3/8" drive ratchet to rotate the tensioner and slip the belt over the last pulley.
• Release the tensioner slowly and double-check the belt is centered on every pulley.

Step 10: Refill and bleed the cooling system

• Install a spill-free coolant funnel kit (specialty) at the radiator fill neck (this is a funnel that seals so you can burp air safely).
• Fill with Subaru-approved coolant (blue, premixed) using a funnel until the level stabilizes.
• Start the engine and set the heater to MAX HOT (this opens the heater core so trapped air can escape).
• Let the engine idle and watch for bubbles in the funnel; add coolant as needed.
• Once the cooling fans cycle and bubbles slow down, shut the engine off and let it cool fully, then top off again.

Step 11: Reinstall undercovers and lower the car

• Reinstall the undertray using a 10mm socket and trim clip removal tool.
• Lower the car using the floor jack.

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✅ After Repair

• Start the engine and check for leaks around the water pump and hose connections.
• Verify the cabin heater blows hot air (a common sign you still have air trapped is weak/no heat).
• After 1-2 normal drives and a full cool-down, recheck coolant level and top off if needed.
• Check the belt path again: it should be fully seated on every pulley groove.

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💰 DIY vs Shop Cost

Shop Cost: $450-$850 (parts + labor)

DIY Cost: $120-$280 (parts only)

You Save: $330-$570 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2.5-4.0 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.