🔧 ILX - Water Pump Replacement

On your ILX, the water pump circulates coolant through the engine and radiator. Replacing it involves draining coolant, removing the drive belt, unbolting the pump, then reinstalling with a new gasket and refilling/bleeding the cooling system.

Difficulty Level: Intermediate | Estimated Time: 2.5-4.0 hours

Assumption: Stock cooling system and accessory-belt-driven water pump.

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⚠️ Safety & Precautions

• ⚠️ Work only on a cold engine; hot coolant can cause severe burns.
• ⚠️ Support the car on jack stands; never rely on a floor jack.
• ⚠️ Keep coolant off belts and pulleys; it can cause slipping.
• ⚠️ Dispose of coolant properly; it’s toxic to people and pets.
• 🔋 Battery disconnect is recommended if your hands/tools will be near the cooling fan (it can turn on automatically).

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks
• Drain pan (at least 10-quart)
• Funnel
• Trim clip remover
• Ratchet (3/8")
• Extension set (3/8")
• 10mm socket
• 12mm socket
• 14mm socket
• Torque wrench (3/8")
• Serpentine belt tool (specialty)
• Flathead screwdriver
• Pliers
• 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 - Qty: 1
• Engine coolant (Honda/Acura Type 2 equivalent, pre-mixed) - Qty: 2 gallons
• Serpentine drive belt - Qty: 1
• Hose clamp(s) - Qty: 1

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📋 Before You Begin

• Park on level ground, set the parking brake, and place wheel chocks behind the rear wheels.
• Let the engine cool completely (ideally overnight).
• Raise the front of the car using a floor jack and support it securely on jack stands.
• If disconnecting the battery: use a 10mm socket to remove the negative terminal and position it so it can’t spring back.
• A serpentine belt tool is a long handle for the belt tensioner.
• A torque wrench tightens bolts to the correct force.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the lower splash shield

• Place a drain pan (at least 10-quart) under the front of the engine area.
• Use a trim clip remover and 10mm socket to remove the clips/bolts holding the lower splash shield, then set it aside.

Step 2: Drain the coolant

• Remove the radiator cap (only if fully cool).
• Use a flathead screwdriver to open the radiator drain plug (petcock) and drain coolant into the drain pan.
• Once drained, close the petcock snugly (do not over-tighten).
• Keep coolant off the drive belt area.

Step 3: Remove the serpentine drive belt

• Locate the belt tensioner at the front of the engine.
• Use a serpentine belt tool (specialty) (or a 14mm socket on the tensioner hex, if accessible) to rotate the tensioner and relieve belt tension.
• Slip the belt off one pulley, then remove the belt fully and set it aside.
• Take a quick photo of belt routing.

Step 4: Disconnect hoses at the water pump (as needed)

• Position the drain pan under the water pump area for remaining coolant.
• Use pliers to slide the spring clamp back, then twist and pull the hose off carefully.
• Use shop towels to catch spills and wipe the area clean.

Step 5: Remove the water pump bolts and water pump

• Use a 10mm socket and ratchet (3/8") with extension set (3/8") to remove the water pump mounting bolts.
• Gently break the pump loose (do not pry against soft aluminum sealing surfaces).
• Remove the pump and old gasket/O-ring.

Step 6: Clean the sealing surface

• Use a plastic gasket scraper to remove any gasket material from the engine mating surface.
• Wipe clean with shop towels until the surface is smooth and dry.
• No gouges—scrape gently.

Step 7: Install the new water pump

• Install the new gasket/O-ring onto the new pump (match the original orientation).
• Position the pump and hand-thread all bolts first to prevent cross-threading.
• Use a torque wrench (3/8") and 10mm socket to tighten evenly in a crisscross pattern: Torque to 12 Nm (9 ft-lbs).

Step 8: Reconnect hoses and reinstall the belt

• Reconnect the hose(s) and reposition clamps using pliers.
• Install the belt using the serpentine belt tool (specialty) to rotate the tensioner and slip the belt onto the last pulley.
• Visually confirm the belt ribs are seated correctly on every pulley.

Step 9: Reinstall the splash shield and lower the car

• Reinstall the splash shield using a trim clip remover and 10mm socket.
• Raise slightly with the floor jack (rated 3-ton minimum), remove jack stands (rated 3-ton minimum), and lower the car.

Step 10: Refill and bleed the cooling system

• Use a funnel to fill the radiator with Engine coolant (Honda/Acura Type 2 equivalent, pre-mixed).
• Fill the coolant reservoir to the MAX line.
• Start the engine and set the heater to HOT (full heat) with the fan on low.
• Let the engine idle until the radiator fan cycles on/off at least once; add coolant as the level drops.
• Watch for leaks at the pump and hose connections.
• Once no more air bubbles appear and heat is steady, reinstall the radiator cap.

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✅ After Repair

• Let the engine cool fully, then recheck the radiator level and reservoir level; top off if needed using the funnel.
• Test drive 10–15 minutes, then inspect for leaks and listen for belt squeal.
• Recheck coolant level again the next morning (cold engine).
• If the temperature gauge rises abnormally, shut off and re-bleed (air trapped).

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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 2.5-4.0 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.