How to Replace the Water Pump on a 2018 GMC Acadia (Step-by-Step Guide)
Tools, parts list, safety tips, torque specs, and coolant refill/bleeding instructions for 2017, 2018, 2020, 2021, 2022, 2023
How to Replace the Water Pump on a 2018 GMC Acadia (Step-by-Step Guide)
Tools, parts list, safety tips, torque specs, and coolant refill/bleeding instructions for 2017, 2018, 2020, 2021, 2022, 2023
🔧 Acadia - Water Pump Replacement
On your Acadia, the water pump is a belt-driven pump on the front of the engine. Replacement involves draining some coolant, removing the drive belt and pump, installing the new pump with a fresh seal, then refilling and bleeding the cooling system.
Difficulty Level: Intermediate | Estimated Time: 2-4 hours
⚠️ Safety & Precautions
- ⚠️ Work on a fully cold engine; hot coolant can cause severe burns.
- ⚠️ Support the vehicle on jack stands; never rely on a floor jack alone.
- ⚠️ Keep hands/clothes clear of the belt path and pulleys.
- ⚠️ Coolant is toxic; use a drain pan and clean spills immediately.
- Battery disconnect is not required, but keep the key away from the vehicle while working.
🔧 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 3-gallon)
- Funnel
- 3/8" drive ratchet
- 3/8" drive extension set
- 10mm socket
- 13mm socket
- 15mm socket
- Serpentine belt tool (specialty)
- Torque wrench (inch-pound and foot-pound)
- Trim clip remover
- Flat plastic scraper
- Shop towels
🔩 Required Parts
HowToo sells all the parts you need for this repair:
- Water pump - Qty: 1
- Water pump seal/gasket - Qty: 1
- Engine coolant (DEX-COOL 50/50 premix) - Qty: As needed to refill
- Serpentine drive belt - Qty: 1 (optional if belt is cracked)
📋 Before You Begin
- Park on level ground, set the parking brake, and chock the rear wheels.
- Let the engine cool completely (overnight is best).
- Raise the front of the vehicle with a floor jack and support with jack stands.
- Remove the lower splash shield if it blocks access (use a trim clip remover and 10mm socket as needed).
- Tip: take a photo of the belt routing before removal.
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Drain the coolant
- Place a drain pan under the radiator drain area.
- Slowly remove the surge tank cap to release any residual pressure.
- Open the radiator drain (if equipped) and drain coolant into the pan. If there’s no drain access, loosen the lower radiator hose clamp using a 10mm socket and carefully crack the hose loose to drain.
Step 2: Remove the drive belt
- Locate the belt tensioner.
- Use a serpentine belt tool (specialty) with a 15mm socket to rotate the tensioner and relieve belt tension.
- Slip the belt off the water pump pulley, then remove the belt from the rest of the pulleys.
- Tip: route the belt out slowly to avoid snagging.
Step 3: Remove any components blocking the water pump
- If your Acadia has brackets/covers in the way, remove them using a 10mm socket or 13mm socket as required.
- Keep bolts grouped by location (a simple “cardboard bolt map” helps).
Step 4: Remove the water pump pulley (if applicable)
- Some versions allow pump removal with the pulley on; if the pulley blocks bolts, remove it.
- Hold the pulley from turning by keeping belt tension on it briefly, or hold it by hand if accessible.
- Remove pulley bolts using a 10mm socket, then remove the pulley.
- Torque to 10 Nm (89 in-lbs) for pulley bolts during reassembly.
Step 5: Remove the water pump
- Place the drain pan under the water pump area (more coolant will spill).
- Remove the water pump bolts using a 10mm socket.
- Pull the pump straight off the engine. If it’s stuck, gently wiggle it—do not pry hard on the sealing surface.
Step 6: Clean the sealing surface
- Use a flat plastic scraper and shop towels to clean the engine’s sealing surface.
- Do not gouge the aluminum. The goal is “clean and smooth,” not “shiny.”
Step 7: Install the new water pump
- Install the new seal/gasket onto the new pump (match how the old one sat).
- Position the pump on the engine and start all bolts by hand.
- Tighten bolts evenly in a crisscross pattern using a 10mm socket.
- Torque to 10 Nm (89 in-lbs) for water pump bolts.
Step 8: Reinstall pulley and belt
- Reinstall the pulley (if removed) using a 10mm socket and torque wrench. Torque to 10 Nm (89 in-lbs).
- Route the belt according to the underhood belt diagram.
- Use the serpentine belt tool (specialty) with a 15mm socket to rotate the tensioner and slip the belt into place.
- Double-check every rib is seated in every pulley groove.
Step 9: Reinstall splash shield and lower the vehicle
- Reinstall the splash shield using the trim clip remover and 10mm socket as needed.
- Lower the vehicle off the jack stands using the floor jack.
Step 10: Refill and bleed the cooling system
- Fill the surge tank with DEX-COOL 50/50 premix using a funnel to the proper level.
- Start the engine and set the heater to HI (this opens the heater core so air can purge).
- Let the engine reach operating temperature; watch the temperature gauge and watch for leaks.
- As the thermostat opens, the coolant level may drop—top off as needed.
- Shut the engine off, let it cool, then recheck and adjust the level.
✅ After Repair
- Inspect for leaks around the pump and hose connections with the engine running.
- Verify the heater blows hot and the temperature stays normal on a test drive.
- After the next full heat-cycle (drive, then cool completely), recheck coolant level and top off if needed.
- Dispose of old coolant properly (most parts stores accept used coolant).
💰 DIY vs Shop Cost
Shop Cost: $650-$1,050 (parts + labor)
DIY Cost: $120-$320 (parts only)
You Save: $330-$930 by doing it yourself!
Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2-4 hours.
🎯 Ready to get started?
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