Every once in a while, a coolant flush should be completed in order to remove deposits or contaminants. The coolant may become contaminated if you are a person that uses the Jeep off-roading quite often. I drive a 2017 Jeep Wrangler and below are steps on how to complete a flush (Please remember to use caution as the engine/coolant may be hot):
5-Gallon bucket or catch pan
12 Quarts of Coolant (3.6L engines take 10.5 quarts) *Preferably Mopar OAT*
3-5 Gallons of distilled or deionized water
Step 1: Pop open the hood of the Jeep.
Step 2: Locate the coolant reservoir. Once you have located it, now you must pump out the coolant from the reservoir.
Step 3: Locate the radiator cap and remove it. *Do not remove the radiator cap when the engine is hot*
Step 4: Locate the petcock. If you are looking at the front of the jeep, it is located on the lower left side of the radiator towards the back. You will then place the bucket below it or use a tube to direct the flow of coolant. Next turn the knob counterclockwise to open the valve and let the radiator drain. Allow to drain for at least 10 minutes. You may need to use a set of pliers to rotate the knob.
Step 5: Close the valve on the petcock.
Step 6: Fill the coolant reservoir to the top with distilled water. You will continue to do this until the reservoir is filled completely. Then install the cover/cap.
Step 7: Fill the radiator all the way up with distilled water. Then install the radiator cap.
Step 8: Make sure the vehicle is in park and the parking brake is engaged. Start the vehicle and allow it to reach normal temperatures.
Step 9: Let the vehicle run until the radiator fans turn on. When the fans turn on then wait an addition 5-10 minutes (This allows the water to circulate through the cooling system).
Step 10: Turn the vehicle off and then let the engine cool down.
Step 11: Once the engine is cooled down then remove both the radiator and reservoir cap. *Remember to use caution as the liquid and components may he hot*
Step 12: Open the valve on the petcock and allow the water to drain. *Replace the bucket if necessary* Allow to drain for 10 mins.
Step 13: Close the valve on the petcock.
Step 14: If a concentrated coolant is purchased, then you would have to mix distilled water with it. It is preferred to run a 50/50 mixture of water and coolant, but that may differ depending on your location. *HOAT and OAT coolant should not be mixed as they may gel up*
Step 15: Pour the coolant into the reservoir and radiator completely.
Step 16: Next, burp the system. There are many ways to do this. One way is to squeeze the radiator hose so that air pockets could leave. Second, you could jack the front of the jeep so that the air bubbles go up the front. Third, with the radiator cap off, run the Jeep and watch as the escapes from the radiator. *An anti spill funnel would help with this situation*
Step 17: Replace both reservoir and radiator cap.
Step 18: Start the vehicle and let the heater run. Do this until the fan kicks on and then let it run an additional 5-10 mins.
Step 19: Turn the vehicle off and repeat steps 15 – 18 as needed to keep coolant at a steady level.
Step 20: Keep an eye out for your coolant levels.
If you have any questions please feel free to ask!