🔧 Prius - Water Pump Replacement

This procedure replaces the engine coolant water pump on your Prius. The pump circulates coolant through the engine, and a failing pump can cause overheating, leaks, or a check engine light.

Difficulty Level: Intermediate | Estimated Time: 2-3 hours

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⚠️ Safety & Precautions

• Let the engine cool completely before opening the cooling system. Hot coolant can burn you.
• Keep hands and tools away from the fan and moving parts.
• Use a scan tool or service mode only if needed for coolant bleeding.
• Hybrid system warning: do not touch orange high-voltage cables. This job does not require HV disconnection if you stay on the coolant system side.
• Battery disconnect is not required for the pump swap itself, but a 12V disconnect can prevent accidental starts if you prefer extra safety.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 12mm socket
• Ratchet
• 3/8-inch extension
• Drain pan
• Funnel
• Pliers
• Torque wrench
• Trim clip tool
• Jack stands
• Floor jack (rated 3-ton minimum)
• Safety glasses
• Mechanic gloves

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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
• Engine coolant - Qty: 1 fill
• New hose clamps - Qty: 1 set, if damaged

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📋 Before You Begin

• Park on level ground and set the parking brake.
• Let the car sit until the coolant is cool to the touch.
• Open the hood and remove the engine undercover if fitted.
• Have a drain pan ready before loosening hoses.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Drain the coolant

• Use a 10mm socket and ratchet to remove the lower splash shield fasteners if needed.
• Place a drain pan under the radiator drain area.
• Open the drain and let enough coolant out so the pump hoses can be removed without spilling much coolant.

Step 2: Access the water pump

• Use a 10mm socket and trim clip tool to remove the upper engine cover or intake ducting if it blocks access.
• On this car, the engine water pump sits at the front of the engine and is reached from the top and lower front area.
• Take a quick photo before disconnecting hoses.

Step 3: Disconnect the hoses

• Use pliers to release the hose clamps.
• Twist the hoses gently and pull them off the pump ports.
• Keep the drain pan underneath to catch leftover coolant.

Step 4: Remove the old water pump

• Use a 12mm socket, ratchet, and extension to remove the pump mounting bolts.
• Pull the pump away from the engine and remove the old gasket.
• Clean the mating surface carefully so the new gasket seals properly.

Step 5: Install the new water pump

• Position the new water pump gasket and install the new pump by hand first.
• Use the 12mm socket and torque wrench to tighten the bolts evenly.
• Torque to 10 Nm (89 in-lbs).
• Reconnect the coolant hoses and make sure the clamps sit fully in place.

Step 6: Refill and bleed the cooling system

• Use a funnel to refill the system with the correct Toyota coolant.
• Fill slowly to reduce air pockets.
• Start the car and let it reach operating temperature while checking for coolant movement, leaks, and air bubbles.
• If equipped with a bleed procedure through the heater controls, set the cabin heat to maximum hot.

Step 7: Reassemble and verify

• Reinstall the splash shield and any removed intake parts using the 10mm socket and trim clip tool.
• Lower the vehicle if it was raised.
• Check coolant level again after the engine cools down.

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✅ After Repair

• Check for leaks around the pump, hoses, and drain plug.
• Verify the heater blows warm air and the engine does not overheat.
• Recheck coolant level after one full heat cycle and top off if needed.
• Watch for warning lights during the next drive.

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💰 DIY vs Shop Cost

Shop Cost: $650-$1,050 (parts + labor)

DIY Cost: $120-$260 (parts only)

You Save: $530-$790 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2-3 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.