How to Replace the Radiator Hose on a 2018 Ford Focus (Upper & Lower)
Step-by-step cooling system hose swap with tools list, parts, coolant refill/bleed tips, and leak checks
How to Replace the Radiator Hose on a 2018 Ford Focus (Upper & Lower)
Step-by-step cooling system hose swap with tools list, parts, coolant refill/bleed tips, and leak checks
đź”§ Focus - Radiator Hose Replacement
Replacing a radiator hose on your Focus is mostly about working safely with coolant, removing the old hose and clamps, and refilling/bleeding the cooling system so it doesn’t overheat. The key is doing it on a fully cool engine and making sure the new hose is fully seated before you clamp it.
Difficulty Level: Intermediate | Estimated Time: 1-2 hours
⚠️ Safety & Precautions
- ⚠️ Only work on a fully cold engine; hot coolant can cause severe burns.
- ⚠️ Depressurize slowly: loosen the coolant reservoir cap a little at first, then remove it fully.
- ⚠️ Support the car safely if you go underneath; never rely on a jack alone.
- ⚠️ Coolant is toxic—catch it in a drain pan and keep away from kids/pets.
- ⚠️ Don’t mix coolant types; use the correct Ford-compatible coolant.
đź”§ 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 with long neck
- Hose clamp pliers (specialty)
- Slip-joint pliers
- Pick tool (small) (specialty)
- 7mm socket
- 8mm socket
- 1/4" ratchet
- Extension (6")
- Flat-blade screwdriver
- Trim clip removal tool (specialty)
- Shop towels
🔩 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
- Engine coolant (Ford-compatible OAT, 50/50 premix) - Qty: 1-2 gallons
đź“‹ Before You Begin
- Park on level ground, set the parking brake, and chock the rear wheels.
- Let the engine cool completely (best: sit overnight).
- Place a drain pan under the radiator area before opening anything.
- “Degas bottle” = the coolant reservoir.
- “Constant-tension clamp” = spring clamp that stays tight.
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Depressurize the cooling system
- Open the hood and locate the coolant reservoir (degas bottle).
- Use your hand to slowly loosen the reservoir cap; pause if you hear pressure release, then remove it once it’s calm.
- Use shop towels around the cap area in case of a small spill.
Step 2: Raise the front (if you’re doing the lower hose)
- If you’re replacing the lower hose, use a floor jack (rated 3-ton minimum) at the front center jacking point and set the car onto jack stands (rated 3-ton minimum).
- Use wheel chocks to prevent rolling.
Step 3: Remove the lower splash shield (if equipped)
- From underneath, remove fasteners using an 8mm socket, 1/4" ratchet, and trim clip removal tool (specialty).
- Set all clips/screws aside so nothing gets lost.
Step 4: Drain coolant to below hose level
- Place the drain pan (at least 2-gallon) under the radiator.
- If accessible, open the radiator drain fitting using a flat-blade screwdriver (some are hand-turn; use only gentle force).
- Drain enough coolant so the level is below the hose you’re replacing (usually 1-2 quarts).
- Close the drain fitting snugly by hand; do not overtighten.
Step 5: Identify your hose (Upper vs Lower)
- Upper radiator hose: runs from the top of the radiator to the engine.
- Lower radiator hose: runs from the bottom of the radiator to the engine area (harder to access from above).
Step 6: Remove the hose clamps
- If you have spring-style clamps, squeeze them with hose clamp pliers (specialty) and slide the clamp back on the hose.
- If you have worm-gear clamps (screw type), loosen them with a 7mm socket and 1/4" ratchet (or flat-blade screwdriver) and slide them back.
- Don’t fully remove clamps unless needed.
Step 7: Break the hose loose and remove it
- Twist the hose gently by hand to break the seal.
- If it’s stuck, use slip-joint pliers to twist carefully (don’t crush the radiator neck).
- If needed, use a pick tool (small) (specialty) to lift the hose edge slightly to let air in, then twist and pull off.
- Pull the hose off both ends and aim it into the drain pan—more coolant will spill.
Step 8: Prepare the connections
- Wipe both fittings (radiator neck and engine-side fitting) using shop towels.
- Inspect the plastic radiator neck for cracks or chips. If damaged, stop—clamping a new hose won’t fix it.
Step 9: Install the new radiator hose
- Slide the clamp(s) onto the new hose before installing it.
- Push the new hose fully onto each fitting until it bottoms out (you shouldn’t see much of the fitting barb).
- Reposition the clamp in the same spot as the original (usually just behind the raised “bead” on the fitting).
Step 10: Tighten/secure the clamps
- For spring clamps, use hose clamp pliers (specialty) to move the clamp into place and release it.
- For worm-gear clamps, tighten with a 7mm socket and 1/4" ratchet until snug—do not overtighten (it can cut the hose).
Step 11: Reinstall the splash shield (if removed)
- Reinstall using the trim clip removal tool (specialty) and tighten fasteners with an 8mm socket, 1/4" ratchet, and extension (6") as needed.
Step 12: Refill and bleed the cooling system
- Insert a funnel with long neck into the coolant reservoir.
- Add Engine coolant (Ford-compatible OAT, 50/50 premix) until it reaches the MAX line.
- Start the engine and set the heater to HOT (full heat) so coolant flows through the heater core.
- Let it idle and watch the temperature gauge; add coolant as the level drops.
- Once the cooling fan cycles on/off at least once, shut the engine off and let it cool fully, then recheck level and top off to MAX.
- If it overheats, shut off immediately.
âś… After Repair
- Check for leaks with the engine idling: look at both ends of the new hose.
- Take a short 10-15 minute drive, then recheck for leaks and recheck coolant level after it cools.
- Verify the heater blows hot and the temperature gauge stays normal.
- Dispose of old coolant properly (most parts stores accept it).
đź’° DIY vs Shop Cost
Shop Cost: $250-$450 (parts + labor)
DIY Cost: $40-$120 (parts only)
You Save: $130-$410 by doing it yourself!
Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.0-1.5 hours.
🎯 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.


















