How to Flush the Radiator of a Jeep Wrangler

If you enjoy the feeling of the open road and going off road from time to time, then a Jeep Wrangler is the perfect vehicle to help you get away for awhile. It can take you places that most vehicles are prohibited from going. But along with your outdoor adventures, your vehicle is subjected to dust and debris that can clog up the cooling system and keep your engine from running its best. If you maintain a practice of flushing out your radiator at least once a year, you will ensure that your Jeep Wrangler keeps performing when you need to get away.

Things You'll Need

  • Bottle of radiator flush Drain pan Pliers Utility knife Radiator flush kit Screwdriver Garden hose attached to water supply Old section of garden hose 5-gallon bucket Antifreeze
  • Make sure the motor is cool before attempting to flush out the radiator. When safe to do so, remove the radiator cap from the radiator. Pour a bottle of radiator flush into the radiator and replace radiator cap. Turn engine on and follow instructions on back of radiator flush bottle. When finished, turn off vehicle and let it cool down. When safe, remove radiator cap.

  • Place a drain pan under the drain plug of radiator to catch coolant as it drains. The drain plug is located at the bottom of the radiator. Turn the drain plug by hand to drain coolant from radiator. If the plug is too tight, use a pair of pliers and gently turn plug. Be careful not to put too much torque on the plug or it will snap off.

  • Locate the heater hose for your Jeep Wrangler. The heater hose runs from the engine to the heater core through the firewall. Once the heater hose is located, find a section of hose that is free of obstructions and cut hose into two pieces with a utility knife.

  • Connect flushing tee from the radiator flush kit to the two sections of heater hose by placing a hose clamp on one end of the hoses and then inserting tee flange into the hose. Move hose clamp to the end of the hose so it can clamp the hose to the flange. Using a screwdriver, tighten the screw on the hose clamp. Repeat process for the other hose and flange. Make sure clamps are tight enough to prevent leakage.

  • Remove cap from flushing tee and connect back flow preventer to the tee. A back flow preventer is included in kit and has a black hose fitting on one end and a yellow fitting on the other. Screw the black hose fitting onto the flushing tee and connect the other end to a garden hose.

  • Locate the splash diverter (included in the flush kit) and attach it to the mouth of the radiator. Push down until you hear it snap into place. Connect old section of garden hose to the end of splash diverter and run the other end into a 5-gallon bucket to catch overflow of coolant.

  • Turn garden hose water supply on and allow it to run through engine and radiator until you see clear liquid running into the bucket. You may need to turn water supply off if the 5-gallon bucket is full and replace with another bucket, repeating the process until liquid runs clear.

  • Shut off water supply, then detach hose from flushing tee and replace tee cap. Remove splash diverter from radiator and refill radiator with coolant and clean water. Reattach radiator cap.