🔧 4Runner - Radiator Hose Replacement

Replacing a radiator hose fixes coolant leaks and helps prevent overheating. On your 4Runner there are two main hoses: the upper radiator hose (top of radiator to engine) and the lower radiator hose (bottom of radiator to engine). The steps below cover both; follow the hose-specific notes as you go.

Difficulty Level: Beginner | Estimated Time: 1.0-2.0 hours

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⚠️ Safety & Precautions

• ⚠️ Only work on a cold engine; hot coolant can burn you.
• ⚠️ Wear gloves and safety glasses; coolant is slippery and irritating.
• ⚠️ Support the truck with jack stands if you lift it; never rely on a jack alone.
• ⚠️ Keep coolant away from pets and kids; it’s toxic and tastes sweet.
• ⚠️ Do not open the radiator cap if the system is hot or pressurized.

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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 2-gallon)
• Funnel
• Slip-joint pliers
• Hose clamp pliers
• Pick tool
• Razor blade scraper
• Shop rags
• 12mm socket
• 3/8" ratchet
• 6" extension
• Torque wrench (10–80 ft-lbs range)

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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
• Toyota Super Long Life Coolant (pink) 50/50 premix - Qty: 1-2 gallons

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📋 Before You Begin

• Park on level ground, set the parking brake, and chock the rear wheels.
• Let the engine cool completely (ideally 2+ hours).
• Place a drain pan under the front of the radiator.
• If you’re doing the lower hose, plan to remove the front skid plate for easier access.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Relieve pressure safely

• Use nitrile gloves and safety glasses.
• Slowly loosen the radiator cap by hand (only when cold). If you hear pressure, tighten it back and wait longer.

Step 2: Drain enough coolant to get below the hose

• Place the drain pan under the radiator drain cock (bottom of radiator).
• Open the drain cock by hand and drain 1–2 quarts so the coolant level drops below the hose you’re replacing.
• Close the drain cock by hand (snug only). Don’t overtighten plastic.

Step 3: (Lower hose) Remove the front skid plate

• Lift the front with a floor jack and support with jack stands.
• Use a 12mm socket, 3/8" ratchet, and extension to remove the skid plate bolts.
• Set the skid plate and bolts aside in order.

Step 4: Move the hose clamps back

• Use hose clamp pliers (a tool that squeezes spring clamps and holds them open) to compress the clamp.
• Slide the clamp a few inches back on the hose so it’s not clamping the fitting anymore.
• If your hose has screw-type clamps, use slip-joint pliers to position them for removal and a screwdriver-style head is not required on this setup; replace with the same style clamps you removed.

Step 5: Remove the old hose

• Twist the hose by hand to break it loose from the radiator neck/engine fitting.
• If it’s stuck, use a pick tool (a small hooked tool) to gently lift the hose edge to let air in.
• Pull the hose off and aim it into the drain pan—more coolant may spill.
• Do not pry hard on the radiator neck. It can crack.

Step 6: Clean and inspect the sealing surfaces

• Use a shop rag to wipe the radiator neck and engine fitting clean.
• If there’s stuck rubber, carefully use a razor blade scraper to remove residue.
• Inspect for cracks on the radiator neck and corrosion on the engine fitting.

Step 7: Install the new hose and clamps

• Slide the new clamps onto the new hose first (use slip-joint pliers if needed).
• Push the new hose fully onto the radiator neck and engine fitting until it bottoms out.
• Use hose clamp pliers to move each clamp into the same position as the original (usually just behind the raised “bead” on the fitting).
• Clamp should sit straight, not crooked.

Step 8: Reinstall the skid plate (if removed)

• Position the skid plate.
• Start all bolts by hand first.
• Tighten using a 12mm socket and torque wrench: Torque to 30 Nm (22 ft-lbs).

Step 9: Refill coolant

• Use a funnel to fill the radiator with Toyota Super Long Life Coolant (pink) 50/50 premix.
• Fill the overflow reservoir to the FULL line.
• Install the radiator cap.

Step 10: Bleed air and check for leaks

• Start the engine and set the heater to HOT and fan to medium.
• Let it idle until warm, then shut it off and let it cool.
• When cold, remove the radiator cap and top off if needed, then recheck the overflow reservoir level.
• Look closely at both ends of the hose for seepage.

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✅ After Repair

• Verify the temperature gauge stays normal on a 10–15 minute drive.
• After the drive and a full cool-down, recheck coolant level in the overflow reservoir and top off to the FULL line.
• Inspect the hose connections again the next morning for any wetness.
• Dispose of old coolant properly (most parts stores accept it).

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💰 DIY vs Shop Cost

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

DIY Cost: $45-$140 (parts only)

You Save: $105-$505 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.0-2.0 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.