🔧 Legacy - Radiator Hose Replacement

Replacing a radiator hose stops coolant leaks and prevents overheating. On your Legacy, you’ll typically replace the upper hose (radiator to engine) and/or the lower hose (radiator to engine/water pump area), then refill and “burp” air out of the cooling system.

Difficulty Level: Intermediate | Estimated Time: 1.5-3.0 hours

Assumption: replacing upper and/or lower radiator hose with stock-style spring clamps.

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⚠️ Safety & Precautions

• ⚠️ Never open the radiator cap on a hot engine; hot coolant can spray and burn.
• ⚠️ Support the car with jack stands on solid ground—never rely on a jack alone.
• ⚠️ Cooling fans can turn on unexpectedly; keep hands/tools clear of the fan area.
• ⚠️ Clean spills immediately; coolant is slippery and toxic to pets.
• 🔋 Battery disconnect is not required for this job.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• Floor jack (rated 2-ton minimum)
• Jack stands (rated 2-ton minimum)
• Wheel chocks
• Drain pan (10-quart minimum)
• Slip-joint pliers
• Hose clamp pliers (specialty)
• Pick tool (small)
• Trim clip removal tool
• 10mm socket
• 12mm socket
• 3/8" drive ratchet
• 3" extension (3/8" drive)
• Flathead screwdriver
• Funnel
• Spill-free funnel kit (specialty)
• Shop towels

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Upper radiator hose - Qty: 1
• Lower radiator hose - Qty: 1
• Radiator hose clamps - Qty: 2-4
• Subaru-compatible coolant (blue, premixed 50/50) - Qty: 2 gallons

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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 fully (ideally 2+ hours).
• 🧼 Put a drain pan under the front of the engine bay area.
• 🧰 If you’re using hose clamp pliers: they lock onto spring clamps to hold them open so you don’t fight the clamp the whole time.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Raise the front of the car (if needed)

• Use a floor jack to lift the front at the proper jacking point.
• Place jack stands and lower the car onto them.
• Set wheel chocks behind the rear wheels.

Step 2: Remove the lower engine undercover (splash shield)

• Use a trim clip removal tool to pop out plastic clips.
• Use a 10mm socket and 12mm socket with a 3/8" drive ratchet and 3" extension to remove bolts.
• Set the shield and hardware aside in a small pile so nothing gets lost.

Step 3: Drain coolant from the radiator

• Place the drain pan under the radiator drain area.
• Slowly loosen the radiator cap on top (only if the engine is fully cool).
• Open the radiator drain (petcock) by hand; use a flathead screwdriver only if needed and gently.
• Let coolant drain until it slows to a drip.
• Tip: keep coolant off belts and connectors.

Step 4: Remove the upper radiator hose (if replacing)

• Locate the upper hose: it runs from the top of the radiator to the engine.
• Use hose clamp pliers (specialty) or slip-joint pliers to squeeze the spring clamp and slide it back on the hose.
• Break the hose seal:
  • Use slip-joint pliers to gently twist the hose back and forth.
  • If stuck, carefully work around the edge with a pick tool (small) to let air in.
• Pull the hose off the radiator neck first, then off the engine fitting.
• Use shop towels to catch any remaining coolant.

Step 5: Remove the lower radiator hose (if replacing)

• Locate the lower hose: it runs from the bottom of the radiator to the engine side.
• Use hose clamp pliers (specialty) to compress the spring clamps and slide them back.
• Twist and remove the hose:
  • Use slip-joint pliers to twist the hose to break it free.
  • Use a pick tool (small) carefully if it’s glued on by age.
• Expect more coolant to drain when the lower hose comes off—keep the drain pan positioned under it.

Step 6: Prep the fittings and install the new hose(s)

• Clean the radiator and engine hose necks with shop towels.
• Slide the clamp(s) onto the new hose before installing it.
• Push the hose fully onto each fitting until it bottoms out.
• Reposition the spring clamp(s) in the same spot they were originally (behind the raised bead on the fitting) using hose clamp pliers (specialty).
• Tip: don’t clamp on the very hose end.

Step 7: Reinstall the undercover

• Reinstall the splash shield using a 10mm socket, 12mm socket, 3/8" drive ratchet, and trim clip removal tool for clips.
• Snug bolts firmly (these are small fasteners—do not overtighten).

Step 8: Refill coolant and bleed air (“burp” the system)

• Install a spill-free funnel kit (specialty) on the radiator fill neck (or use a funnel carefully).
• Pour in Subaru-compatible coolant (blue, premixed 50/50) until the radiator stays full.
• Fill the overflow reservoir to the FULL line.
• Start the engine and set the heater to HOT with the fan on low.
• Let the engine idle and watch for air bubbles in the funnel; add coolant as the level drops.
• As the engine warms up, gently squeeze the upper hose with gloved hands to help move trapped air.
• Once bubbles stop and the heat blows hot, shut the engine off and let it cool completely, then top off radiator and reservoir as needed.

Step 9: Check for leaks

• With the engine running, inspect both hose connections with a flashlight (use shop towels to wipe and re-check).
• Look underneath for drips near the lower hose and drain area.

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✅ After Repair

• 🧪 Drive 10–15 minutes, then park and check for leaks again after it cools.
• 🌡️ Over the next 2–3 trips, recheck the overflow reservoir level and top off to the FULL line when cold.
• 🧼 Properly dispose of used coolant—most parts stores accept it for recycling.

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💰 DIY vs Shop Cost

Shop Cost: $250-$550 (parts + labor)

DIY Cost: $60-$180 (parts only)

You Save: $190-$370 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5-3.0 hours.

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🎯 Ready to get started?

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