Details

• Brand:

  

• SKU:

  21503-9NB0A

• Positions: Lower
• Other Names:

  Radiator Coolant Hose, Hose-Lower

• Description:

  Noticing coolant leaks or overheating issues? Restore proper coolant circulation and protect your engine from heat damage with the OEM Nissan Lower Radiator Hose (Part #21503-9NB0A), designed for an exact factory fit and long-term durability.

  Lower Radiator Hose (21503-9NB0A) – OEM Replacement Part for Nissan

  This genuine Nissan lower radiator hose carries coolant between the radiator and engine block, helping regulate operating temperature and prevent overheating. Built from high-quality, heat- and pressure-resistant rubber, this hose ensures leak-free performance and precise fitment on your Pathfinder’s cooling system.

  Specifications

  • Part Type: Lower Radiator Hose

  • Function: Transfers coolant from radiator to engine block

  • Construction: OEM-grade reinforced rubber with factory-formed bends and couplers

  • Position: Lower (engine to radiator)

  • Includes: One (1) lower radiator hose assembly

  Compatible Nissan Models

  • 2012 – 2021 Nissan Pathfinder (R52US)

  Fitment may vary by engine or trim level. To confirm compatibility for your specific vehicle, click here

  and enter your VIN using the “Search by VIN #” feature before ordering.

  Key Features

  • Genuine Nissan part ensures precise fitment and factory-quality sealing

  • Maintains proper engine cooling and fluid circulation

  • Heat- and pressure-resistant rubber for long service life

  • Factory-formed bends prevent kinking or restricted coolant flow

  • Direct-fit OEM replacement — no cutting or modification required

  Important Installation Note

  When replacing the lower radiator hose, it’s strongly recommended to:

  • Drain and refill the cooling system with fresh coolant

  • Inspect upper radiator hose and heater hoses for wear or swelling

  • Check hose clamps and connections for proper tension and corrosion

  • Bleed air from the cooling system to prevent air pockets and temperature fluctuations

  Proper coolant mixture and system bleeding are essential to avoid overheating and ensure long-term performance.

  Failing to Replace a Worn Radiator Hose Can Lead To:

  • Coolant Leaks: From cracks, swelling, or loose connections

  • Overheating: Restricted flow or pressure loss in the cooling circuit

  • Loss of Cabin Heat: From reduced coolant circulation

  • Engine Damage: From coolant loss or overheating under load

  • Unexpected Breakdowns: Due to burst hoses during high-temperature operation

  Related Components to Inspect or Replace

  • Upper Radiator Hose: Often replaced together for balanced system maintenance

  • Thermostat & Gasket: Ensures proper coolant flow and temperature regulation

  • Radiator Cap: Maintains correct system pressure

  • Coolant Reservoir Hose: Check for cracks or leaks near fittings

  • Nissan Genuine Coolant (Blue): Always refill with Nissan-approved coolant for optimal protection

  Order with Confidence

  Order the OEM Nissan Lower Radiator Hose (21503-9NB0A) to maintain your Pathfinder’s cooling system efficiency and prevent future leaks or overheating. Genuine Nissan hoses provide the exact fit, material quality, and durability your vehicle was designed for.

  Restore Your Nissan with Genuine Accessories!

  Looking to keep your Nissan running and looking its best? Shop factory-direct Nissan accessories — from maintenance items to protection kits — at parts.chapmannissan.com

  . Whether you’re maintaining performance or enhancing convenience, you’ll find all genuine parts in one place.

  Why Buy OEM Nissan Parts from Chapman Nissan?

  Every part sold by Chapman Nissan is 100% genuine from Nissan, engineered for exact factory specifications and reliability. Unlike aftermarket hoses, OEM Nissan hoses match the correct inner diameter, bend angles, and connection depth for secure, leak-free installation.

  • Fast, secure shipping from a certified Nissan dealer

  • VIN verification available for guaranteed fit

  • Trusted by Nissan owners and professional technicians

  Cooling System FAQ

  Q: Does this hose include clamps?
  A: Yes this hose does include the clamps

  Q: Should I replace the upper hose at the same time?
  A: Yes, it’s recommended to replace both radiator hoses together to ensure consistent pressure and reliability.

  Q: What coolant should I use?
  A: Always refill with Nissan-approved coolant — check your vehicle’s service manual for the correct specification.

  Q: Do I need to bleed the system after installation?
  A: Yes. Proper bleeding ensures no trapped air remains, preventing overheating or erratic temperature readings.

• Condition: New
• Applications: 3.5L.

WARNING: California Proposition 65

×

California Proposition 65

WARNING: Cancer and reproductive harm - www.P65Warnings.ca.gov