Mishimoto MMHOSE-WR6-12MBK Radiator Hose Kit for 2012–2018 Jeep Wrangler JK

Important 2018 JK versus JL Warning

Jeep sold both the older Wrangler JK and redesigned Wrangler JL during the 2018 model year. This hose kit fits the JK platform only.

Before ordering for a 2018 Wrangler, verify:

• The vehicle is identified as a Wrangler JK
• The VIN and production information match the JK platform
• The original hose shapes match the product images
• The radiator and engine connections retain JK routing

It does not fit the 2018-and-newer Wrangler JL. Apparently giving two different generations the same model year seemed perfectly reasonable.

Five-Layer Silicone Construction

Each hose is manufactured from five layers of silicone with embedded heat-resistant fibers. This construction provides improved resistance to cooling-system pressure, engine heat and deterioration compared with aging factory rubber hoses.

Features include:

• Five-layer reinforced silicone
• Heat-resistant embedded fibers
• Maximum temperature rating of 330°F
• Improved heat and pressure tolerance
• Preformed JK-specific routing
• Matte-black finish
• Direct replacement-style installation
• Mishimoto Lifetime Warranty

The matte-black finish provides the durability of silicone without making the engine bay look like it lost a fight with a highlighter.

What’s Included?

The package contains:

• One matte-black upper radiator hose
• One matte-black lower radiator hose
• Four worm-gear hose clamps

This kit replaces the main radiator hoses. It does not include every heater, bypass, oil-cooler or expansion-tank hose in the Wrangler cooling system.

Suitable for Stock and Modified Jeeps

The kit follows the original 3.6L JK cooling-system routing and is appropriate for stock vehicles as well as many modified Jeeps.

Verify clearance carefully when the vehicle has:

• An aftermarket radiator
• Electric-fan modifications
• A body lift
• Relocated accessories
• An engine conversion
• An aftermarket supercharger
• Custom coolant plumbing
• Additional transmission or power-steering coolers

Off-road modifications may not directly alter hose fitment, but they can change airflow, operating load and access around the cooling system.

Signs Your JK Radiator Hoses Need Replacement

Replace the hoses if you notice:

• Cracks near either connection
• Soft or swollen sections
• Coolant staining around a clamp
• Oil contamination
• Abrasion against another component
• A hose collapsing after shutdown
• Persistent coolant odor
• Recurring coolant loss
• Steam or visible leakage
• Engine overheating

Use our coolant-leak diagnostic guide if the source is unclear. Inspect the radiator, thermostat housing, oil-cooler assembly, water pump and expansion tank in addition to the hoses.

Installation Overview

Only open the cooling system after the engine has cooled completely.

A typical installation involves:

1. Confirm that the vehicle is a 2012–2018 JK or JKU.
2. Photograph the original hose routing.
3. Drain the coolant into a suitable container.
4. Remove components blocking access as required.
5. Release the original hose clamps.
6. Carefully remove the upper and lower hoses.
7. Inspect every radiator and engine connection.
8. Clean the sealing surfaces.
9. Compare the replacement hoses with the originals.
10. Install each hose without twisting or stretching it.
11. Position each clamp behind the raised connection bead.
12. Verify clearance from the fan, belt, pulleys and sharp brackets.
13. Refill with coolant meeting Jeep specifications.
14. Bleed trapped air from the system.
15. Confirm cooling-fan operation.
16. Check for leaks at operating temperature.
17. Recheck the coolant level after the engine cools.

Mishimoto recommends approximately 22 in-lb or 2.5 N·m for its worm-gear clamps. The published operating range is 18–27 in-lb; do not exceed 27 in-lb. More torque does not automatically produce more sealing. Sometimes it just produces damaged parts with impressive efficiency.

Use our cooling-system flush guide if the coolant is contaminated, mixed or overdue for replacement.

Inspect the Complete Pentastar Cooling System

New hoses will not correct a failed thermostat, radiator, water pump or oil-cooler housing. While the system is drained, inspect:

• Radiator core and tanks
• Water pump and weep hole
• Thermostat housing
• Expansion tank and cap
• Cooling fan and controls
• Oil-cooler/filter housing area
• Heater hoses
• Serpentine belt and tensioner
• Coolant condition
• Evidence of combustion leakage

Our complete cooling-system guide explains how these components interact.

For an overheating Wrangler, use these diagnostic resources:

• Why a vehicle overheats while driving
• Bad thermostat versus bad water pump
• Seven signs of a failing radiator
• Car overheating while the heater blows cold
• Can radiator stop-leak cause damage?
• When should you stop driving?

Frequently Asked Questions

What years does MMHOSE-WR6-12MBK fit?

It fits 2012–2018 Jeep Wrangler JK and Wrangler Unlimited JKU models equipped with the 3.6L Pentastar V6.

Does it fit a 2018 Wrangler JL?

No. It fits the carryover 2018 Wrangler JK, not the redesigned JL.

Does it fit the four-door Wrangler Unlimited?

Yes. It fits compatible 2012–2018 Wrangler Unlimited JKU models with the 3.6L engine.

Does it fit a 2011 Wrangler?

No. The 2011 JK used the earlier 3.8L V6 and requires a different hose kit.

Does it fit every trim level?

It fits applicable 3.6L JK and JKU trims, including Sport, Sahara and Rubicon. Verify platform, engine and hose routing rather than relying only on the trim name.

Are the upper and lower hoses included?

Yes. The kit includes both primary radiator hoses and four clamps.

Is this the gloss-black version?

No. MMHOSE-WR6-12MBK is the matte-black version. MMHOSE-WR6-12BK identifies the conventional black version.

Will it fit an aftermarket aluminum radiator?

It should fit a direct-replacement radiator retaining factory connection positions and diameters. Measure custom radiators before ordering.

Will silicone hoses prevent trail overheating?

They help prevent hose-related leaks or failures but cannot compensate for poor airflow, a clogged radiator, failed fan, defective thermostat, weak water pump or excessive engine load.

Product Specifications