How to Replace the Upper & Lower Radiator Hoses on a 2021 Jeep Gladiator
Step-by-step DIY guide with tools, parts list, coolant refill/bleeding tips, and leak checks
How to Replace the Upper & Lower Radiator Hoses on a 2021 Jeep Gladiator
Step-by-step DIY guide with tools, parts list, coolant refill/bleeding tips, and leak checks
đź”§ Gladiator - Radiator Hose Replacement
Replacing a radiator hose stops coolant leaks and prevents overheating. You’ll remove the old hose, install a new one with good clamps, then refill and bleed the cooling system so it doesn’t trap air.
Difficulty Level: Intermediate | Estimated Time: 1.0-2.0 hours
⚠️ Safety & Precautions
- ⚠️ Never open the radiator cap on a hot engine; hot coolant can spray and burn you.
- ⚠️ Support the truck safely if you lift it; use jack stands, not just a jack.
- ⚠️ Coolant is toxic—keep it away from kids/pets and clean spills immediately.
- ⚠️ Don’t mix coolant types; use the correct OAT-spec coolant for your Gladiator.
- Battery disconnect is not required for this job.
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 3-gallon)
- Funnel
- Hose clamp pliers
- Pick tool
- Razor blade scraper
- Shop towels
- 7mm socket
- 1/4" drive ratchet
- Flashlight
🔩 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
- Engine coolant (OAT, MS.90032 compatible, premix) - Qty: 2-3 gallons
đź“‹ Before You Begin
- Park on level ground, set the parking brake, and chock the wheels.
- Let the engine cool completely (best is overnight).
- Set the HVAC to heat (HOT) and fan to low when you’re ready to bleed air after refill.
- Have a drain pan ready; coolant will run down crossmembers and splash.
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Identify which hose you’re replacing
- The upper radiator hose runs from the top of the radiator to the engine (thermostat/water outlet area).
- The lower radiator hose runs from the bottom of the radiator to the engine/water pump area.
- Use a flashlight to trace the hose and confirm the ends.
Step 2: Relieve pressure safely
- With the engine cold, slowly loosen the coolant pressure cap (on the reservoir) by hand.
- Use nitrile gloves and safety glasses in case there’s any trapped pressure.
Step 3: Drain enough coolant to drop the level below the hose
- Place a drain pan (at least 3-gallon) under the radiator area.
- If access is tight, lift the front with a floor jack (rated 3-ton minimum) and support with jack stands (rated 3-ton minimum).
- Drain coolant from the radiator drain point (if accessible) or by loosening the lower hose carefully.
- Only drain what you need to minimize mess.
Step 4: Remove the hose clamps
- Use hose clamp pliers to compress and slide spring-style clamps back away from the hose end.
- If your hose uses a screw clamp, loosen it with a 7mm socket and 1/4" drive ratchet.
- Take a photo of clamp positions first.
Step 5: Break the hose loose and remove it
- Twist the hose by hand to break it free from the fitting.
- If it’s stuck, carefully work a pick tool under the hose edge to release it.
- Pull the hose off and aim it into the drain pan (at least 3-gallon) to catch remaining coolant.
- Torque to N/A (hose connections use clamps, not bolts).
Step 6: Clean and inspect the hose fittings
- Use shop towels to wipe the radiator neck and engine-side fitting clean.
- Remove stuck rubber residue gently with a razor blade scraper (light pressure only).
- Inspect the plastic/metal necks for cracks, pitting, or broken ridges that the clamp seals against.
Step 7: Install the new radiator hose
- Slide the clamps onto the new hose before installing it.
- Push the hose fully onto each fitting until it seats against the stop/bead.
- Position the clamps in the same spot as original (typically behind the raised bead).
- Use hose clamp pliers to release spring clamps into place, or tighten screw clamps with a 7mm socket and 1/4" drive ratchet.
- Torque to N/A for spring clamps (they self-tension). For screw clamps, tighten snug—do not crush plastic fittings.
Step 8: Refill coolant
- Use a funnel to refill the reservoir with Engine coolant (OAT, MS.90032 compatible, premix).
- Fill to the MAX line (cold) to start.
Step 9: Bleed air from the cooling system
- Start the engine and let it idle; set HVAC to HOT and fan low.
- Watch for leaks at both ends of the hose with a flashlight.
- If equipped with a bleeder screw near the coolant outlet, open it carefully with a 7mm socket until coolant flows without bubbles, then close it.
- Torque to N/A (close bleeder gently—do not over-tighten).
- As the engine warms up, top off coolant as needed using a funnel.
- Stop if the temp gauge rises abnormally.
Step 10: Final level check
- Shut the engine off and let it cool fully.
- Recheck the reservoir level and add coolant if needed using a funnel.
- Inspect for dried coolant trails and recheck clamp positioning with hose clamp pliers.
âś… After Repair
- Test drive 10-15 minutes and watch the temperature gauge.
- Park, let it cool, and recheck the coolant level again (air can burp out on the first heat cycle).
- Look underneath for drips and re-inspect both hose ends with a flashlight.
- Dispose of old coolant properly (hazardous waste facility).
đź’° DIY vs Shop Cost
Shop Cost: ₹6,000-₹15,000 (parts + labor)
DIY Cost: ₹1,800-₹6,500 (parts only)
You Save: ₹4,200-₹8,500 by doing it yourself!
Shop labor rates vary but typically run ₹800-₹2,000/hour. This repair takes a shop approximately 1-2 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.


















