🔧 MDX - Water Pump Replacement

On your MDX, the water pump is driven by the timing belt, so replacing it requires removing the timing belt and setting the engine to precise timing marks. This is usually done together with a timing belt kit because most of the labor is the same.

Difficulty Level: Advanced | Estimated Time: 5-8 hours

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⚠️ Safety & Precautions

• ⚠️ Let the engine cool fully before opening the radiator cap (hot coolant can spray).
• ⚠️ Support the vehicle securely on jack stands before working underneath.
• ⚠️ Support the engine before removing the right-side engine mount.
• ⚠️ Do not rotate the engine with the timing belt removed unless instructed (valve timing can be lost).
• ⚠️ Battery disconnect is recommended to prevent accidental cranking.

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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
• Shop towels
• 1/4" drive ratchet
• 3/8" drive ratchet
• 1/2" drive breaker bar (24" minimum)
• Socket set (8mm-19mm)
• 10mm socket
• 12mm socket
• 14mm socket
• 17mm socket
• 19mm socket
• Torque wrench (10-250 Nm range)
• Serpentine belt tool (14mm) (specialty)
• Crankshaft pulley holding tool (specialty)
• Crank pulley socket (19mm, heavy-duty)
• Pry bar (12")
• Trim clip remover
• Flathead screwdriver
• Needle-nose pliers
• Hose clamp pliers
• Gasket scraper (plastic)
• Engine support bar (specialty)

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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
• Timing belt - Qty: 1
• Timing belt tensioner - Qty: 1
• Timing belt idler pulley - Qty: 1
• Timing belt auto-tensioner pulley (if included in kit) - Qty: 1
• Serpentine belt - Qty: 1
• Engine coolant (Honda/Acura Type 2 premix) - Qty: 2 gallons
• RTV silicone (sensor-safe) - Qty: 1

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📋 Before You Begin

• Park on level ground, set the parking brake, and chock the rear wheels.
• Disconnect the negative battery cable using a 10mm socket.
• Raise the front-right corner with a floor jack and support with jack stands.
• Remove the right-front wheel using a 19mm socket.
• Remove the right-side splash shield/inner fender liners using a trim clip remover and 10mm socket.
• Take photos before you remove anything.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Drain the coolant

• Place a drain pan (at least 10-quart) under the radiator drain.
• Slowly open the radiator cap by hand (only when cool), then open the drain cock (use a flathead screwdriver if needed).
• Drain into the pan, then close the drain cock.

Step 2: Remove the serpentine belt

• Rotate the belt tensioner with a serpentine belt tool (14mm) (specialty) to release tension.
• Slip the belt off and remove it from the engine bay.
• Sketch the belt routing first.

Step 3: Support the engine and remove the right engine mount

• Install an engine support bar (specialty) to hold the engine from above. (An engine support bar is a crossbar that holds the engine when a mount is removed.)
• Remove mount fasteners using a 14mm socket and 17mm socket.
• During reassembly, tighten mount fasteners to Torque to 64 Nm (47 ft-lbs) for bracket bolts and Torque to 76 Nm (56 ft-lbs) for the mount through-bolt.

Step 4: Remove the crankshaft pulley (harmonic balancer)

• Install the crankshaft pulley holding tool (specialty). (This tool locks the pulley so the bolt can be loosened safely.)
• Use a 19mm socket and 1/2" drive breaker bar to loosen and remove the crank pulley bolt.
• Remove the pulley; use a pry bar (12") gently only if needed.
• During reassembly, tighten the crank bolt to Torque to 245 Nm (181 ft-lbs).

Step 5: Remove the timing belt covers

• Remove the upper and lower timing covers using a 10mm socket and 12mm socket.
• Keep bolts organized by cover location.

Step 6: Set cylinder #1 to TDC on the compression stroke

• Turn the crankshaft clockwise using a 19mm socket and 1/2" drive ratchet until the timing marks align on the cam sprockets and crank sprocket.
• Confirm the cam marks line up with the marks on the rear cover.
• Only rotate clockwise.

Step 7: Remove the timing belt tension and timing belt

• Remove the timing belt tensioner bolts using a 12mm socket.
• Remove the timing belt tensioner and then slip the timing belt off the sprockets.
• During reassembly, tighten tensioner mounting bolts to Torque to 44 Nm (33 ft-lbs).

Step 8: Remove the water pump

• Place a drain pan (at least 10-quart) under the pump area (more coolant will spill).
• Remove the water pump mounting bolts using a 10mm socket.
• Remove the pump; use a plastic gasket scraper to separate it if it’s stuck.
• Clean the mating surface with a gasket scraper (plastic) and shop towels until it’s smooth and dry.

Step 9: Install the new water pump

• Install the new gasket/O-ring onto the new pump.
• Position the pump and start all bolts by hand.
• Tighten water pump bolts evenly using a 10mm socket and finish with a torque wrench: Torque to 12 Nm (9 ft-lbs).
• If your pump design calls for small dabs of sealant, apply a very thin film of RTV silicone (sensor-safe) only where specified by the gasket design.

Step 10: Install the timing components and timing belt

• If replacing pulleys, install them using the correct socket and a torque wrench; tighten the idler pulley bolt to Torque to 54 Nm (40 ft-lbs).
• Route the new timing belt over the sprockets, keeping the belt tight on the non-tensioned side.
• Install the timing belt tensioner using a 12mm socket, then torque to Torque to 44 Nm (33 ft-lbs).
• Rotate the engine two full turns clockwise using a 19mm socket, then re-check all timing marks.
• If marks don’t align, redo it.

Step 11: Reinstall timing covers and crank pulley

• Reinstall timing covers using a 10mm socket and 12mm socket.
• Reinstall the crank pulley and bolt using a 19mm socket and crankshaft pulley holding tool (specialty).
• Torque the crank bolt to Torque to 245 Nm (181 ft-lbs).

Step 12: Reinstall the engine mount, serpentine belt, and shields

• Reinstall the right engine mount using a 14mm socket and 17mm socket.
• Tighten mount fasteners to Torque to 64 Nm (47 ft-lbs) and the mount through-bolt to Torque to 76 Nm (56 ft-lbs).
• Install the serpentine belt using a serpentine belt tool (14mm) (specialty).
• Reinstall splash shields using a trim clip remover and 10mm socket.
• Reinstall the wheel and snug lug nuts using a 19mm socket. Lower the vehicle and torque lug nuts to Torque to 127 Nm (94 ft-lbs).

Step 13: Refill and bleed the cooling system

• Refill with Honda/Acura Type 2 premix using a funnel.
• Set the heater to full HOT and fan to low.
• Start the engine and let it warm up; keep topping off the reservoir as the level drops.
• If equipped with a bleed bolt, open it carefully using a 12mm socket until coolant flows without bubbles, then close it.
• Install the radiator cap once bubbling stops and heat is steady.

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✅ After Repair

• Check for coolant leaks around the water pump and timing cover area with the engine running.
• Verify the temperature gauge stays normal and the heater blows hot.
• After the first drive and full cool-down, recheck the coolant reservoir level and top off if needed.
• Listen for belt squeal or abnormal chirping; recheck belt routing if heard.

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💰 DIY vs Shop Cost

Shop Cost: $1,200-$2,200 (parts + labor)

DIY Cost: $250-$650 (parts only)

You Save: $550-$1,950 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 5-8 hours.

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🎯 Ready to get started?

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