🔧 Odyssey - Water Pump Replacement

On your Odyssey, the water pump is driven by the timing belt. Replacing it means removing the timing belt and related components, then installing a new pump and refilling/bleeding the cooling system.

Difficulty Level: Advanced | Estimated Time: 4-7 hours

Assumption: J35 V6 timing-belt-driven water pump (most common setup).

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⚠️ Safety & Precautions

• ⚠️ Let the engine cool completely before draining coolant; hot coolant can burn you.
• ⚠️ Support the van securely on jack stands; never work under a jack alone.
• ⚠️ Disconnect the negative battery cable to prevent accidental cranking.
• ⚠️ Do not rotate the crankshaft or camshafts with the timing belt removed unless instructed; valve-to-piston contact can occur.
• ⚠️ Keep fingers clear when setting the belt tension; the tensioner is spring-loaded.

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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 2-gallon)
• Funnel
• Metric socket set (8mm-19mm)
• 10mm socket
• 12mm socket
• 14mm socket
• 17mm socket
• 19mm socket
• 3/8" ratchet
• 1/2" breaker bar
• Torque wrench (10-250 ft-lb range)
• Serpentine belt tool or 14mm box wrench
• Honda crank pulley holding tool (specialty)
• Harmonic balancer puller (specialty)
• Trim clip removal tool
• Flat-blade screwdriver
• Pliers
• Gasket scraper (plastic)
• Shop rags
• Paint marker

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Water pump - Qty: 1
• Water pump gasket or O-ring - Qty: 1
• Timing belt - Qty: 1
• Timing belt tensioner - Qty: 1
• Timing belt idler pulley - Qty: 1
• Timing belt tensioner pulley - Qty: 1
• Engine coolant (Honda Type 2 premix equivalent) - Qty: 2-3 gallons
• Accessory drive belt - Qty: 1
• Crankshaft pulley bolt - Qty: 1

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📋 Before You Begin

• Park on level ground, set the parking brake, and place wheel chocks behind the rear tires.
• Disconnect the battery using a 10mm socket (negative cable first).
• Raise the front and support it with jack stands at the proper lift points.
• Remove the right front wheel using a 19mm socket.
• Take photos as you go. They help a lot during reassembly.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Drain the coolant

• Place a drain pan under the radiator drain.
• Open the radiator cap to vent, then open the drain using pliers or by hand (depending on drain style).
• Drain the coolant fully, then close the drain.

Step 2: Remove the lower splash shield (right side)

• Remove clips/screws using a trim clip removal tool and 10mm socket.
• Set the shield and fasteners aside.

Step 3: Remove the accessory (serpentine) belt

• Use a serpentine belt tool or 14mm box wrench to rotate the belt tensioner and slip the belt off.
• Draw the belt routing first.

Step 4: Remove the crankshaft pulley

• Install the Honda crank pulley holding tool (specialty) to hold the pulley.
• Loosen the crank bolt using a 19mm socket and 1/2" breaker bar.
• Remove the pulley; if it’s stuck, use a harmonic balancer puller (specialty).
• Torque to 245 Nm (181 ft-lb) for the crank bolt during reassembly.

Step 5: Remove the timing belt covers

• Remove the upper and lower timing covers using a 10mm socket.
• Keep bolts organized by location/length.

Step 6: Support the engine and remove the right-side engine mount

• Position a floor jack (rated 3-ton minimum) under the engine with a block of wood (spreads the load).
• Remove the right engine mount fasteners using a 14mm socket and 17mm socket as needed.
• Lift or lower the jack slightly to relieve bolt tension while removing them.

Step 7: Set the engine to Top Dead Center (TDC)

• Rotate the crankshaft clockwise using a 19mm socket and 1/2" breaker bar until timing marks align.
• Mark the belt and sprockets with a paint marker for extra reference.
• Only rotate clockwise.

Step 8: Release tension and remove the timing belt

• Remove the timing belt tensioner bolts using a 12mm socket.
• Remove the belt carefully and keep the cam/crank from moving.
• Torque to 54 Nm (40 ft-lb) for the tensioner bolts during reassembly.

Step 9: Remove the water pump

• Place the drain pan under the pump area (more coolant will spill).
• Remove the water pump mounting bolts using a 10mm socket or 12mm socket (bolt sizes vary by position).
• Remove the pump and gasket/O-ring.
• Clean the mating surface using a plastic gasket scraper and shop rags.
• Torque to 12 Nm (9 ft-lb) for water pump bolts during reassembly.

Step 10: Install the new water pump

• Install the new gasket/O-ring on the new pump (verify it sits flat).
• Position the pump and hand-start all bolts.
• Tighten evenly in a crisscross pattern using a torque wrench: Torque to 12 Nm (9 ft-lb).

Step 11: Install idlers/tensioner and reinstall the timing belt

• Replace the idler pulleys using a 14mm socket as needed.
• Install the new tensioner using a 12mm socket, then torque with a torque wrench: Torque to 54 Nm (40 ft-lb).
• Route the new timing belt, keeping the belt tight on the non-tensioned side.
• Release/activate the tensioner per the new part design.

Step 12: Verify timing by hand-rotating the engine

• Rotate the crankshaft clockwise two full turns using a 19mm socket and 1/2" breaker bar.
• Recheck that timing marks align exactly.
• If marks do not line up, stop and correct belt placement before proceeding.

Step 13: Reassemble covers, mount, and crank pulley

• Reinstall timing covers using a 10mm socket.
• Reinstall the right engine mount using a 14mm socket and 17mm socket, then tighten securely with a torque wrench to the specification for your mount fasteners.
• Reinstall the crank pulley and install a new crank bolt (recommended).
• Hold the pulley with the Honda crank pulley holding tool (specialty) and torque the crank bolt with a torque wrench: Torque to 245 Nm (181 ft-lb).

Step 14: Reinstall the serpentine belt, wheel, and splash shield

• Install the accessory belt using a serpentine belt tool or 14mm box wrench.
• Reinstall the splash shield using a trim clip removal tool and 10mm socket.
• Reinstall the wheel using a 19mm socket, then torque lug nuts with a torque wrench: Torque to 127 Nm (94 ft-lb).

Step 15: Refill and bleed the cooling system

• Refill the radiator with Honda Type 2 premix equivalent coolant using a funnel.
• Start the engine and set heat to HOT (this helps purge air).
• Let it reach operating temperature, topping off as the level drops.
• Shut off, let cool, then recheck radiator and reservoir levels.

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✅ After Repair

• Check for coolant leaks around the water pump area with the engine idling.
• Road test 10-15 minutes, then recheck coolant level after a full cool-down.
• Watch the temperature gauge closely for the first few drives.
• If you hear slapping/whining from the timing cover area, shut down and recheck belt routing and tension.

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💰 DIY vs Shop Cost

Shop Cost: $900-$1,600 (parts + labor)

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

You Save: $720-$1,150 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 4-7 hours.

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🎯 Ready to get started?

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