How to Flush & Fill a Nissan Frontier Coolant System

The coolant in your Nissan Frontier is responsible for maintaining proper engine temperatures. Over time, the coolant starts to break down, picks up engine particles, and becomes sludgy. When this happens, the engine fails to maintain proper temperatures, reducing the life of your engine. Completing a flush & fill on your Nissan Frontier coolant system helps maintain a healthy, long-lasting engine.

Things You'll Need

  • Pliers
  • Drainage containers
  • Garden hose
  • Water supply
  • Three gallons radiator coolant
  • Three gallons distilled water
  • Remove the lower radiator hose from the Frontier's radiator. Do this by squeezing the compression tabs on the radiator hose clamp together with a pair of pliers, then by pulling the hose off the radiator inlet tube. Drain the contents of the radiator hose and the radiator into a drainage container. The Frontier holds about five gallons of fluid.

  • Open the radiator cap and place a garden hose into the hole. Do not use a sprayer nozzle. The high-pressure water from a nozzle could damage the inner lining of the radiator.

  • Flow water through the radiator, aiming the hose at the sidewalls of the radiator until clean water flows from the bottom of the radiator. Again, catch all fluid in a drainage pan.

  • Reattach the radiator hose to the lower radiator inlet tube. Secure the hose with the hose clamp.

  • Pour a 50/50 mix of radiator coolant and distilled water into the radiator.

  • Run the Frontier for about five minutes with the radiator cap off to force air out off the cooling system. Stop the engine and top the radiator off with a 50/50 mix of radiator coolant and distilled water. Repeat this process until the radiator no longer requires additional fluid. Place the cap back on the radiator when finished.