Motorhomes put a unique strain on their cooling systems. While the engine works a bit harder to move all the weight involved in a house on wheels, it generates more heat, which must be carried away by the cooling system. In order to ensure the system does all it can to remove the engine heat, the system should undergo scheduled maintenance on a regular basis. Flushing the cooling system and radiator can be performed by a professional repair shop, or by anyone with some basic mechanical aptitude.
Place the catch pan underneath the radiator so that it sits directly underneath the bottom radiator hose outlet.
Use the socket set to disconnect the lower radiator hose from the radiator by loosening the hose clamp and then sliding the hose off the radiator outlet.
Lift the end of the hose upward and slide the garden hose into it. Have a helper turn the water on while you hold the garden hose into the radiator hose. Once the water starts flowing, compress the end of the radiator hose around the garden hose as tightly as you can to prevent water from backing out of the hose.
Let the water run until clear water begins pouring from the lower radiator hose outlet on the radiator. Depending on the condition of your cooling system and the length of time since the last service, this may take anywhere from five to 20 minutes.
Turn the water off and allow the excess to drain back out of the bottom radiator hose into the catch pan.
Reattach the lower radiator hose in reverse of how you removed it.
Fill the radiator with an equal mixture of coolant and distilled water. You will most likely need to fill the radiator through the coolant overflow bottle. Depending on the particular Motorhome’s set up, this could take up to 4 gallons of each.
Close the system and start the engine. Allow it to run for two or three minutes and then shut it off. Top off the system with a 50/50 mixture of coolant and distilled water. Recheck the coolant level and add as needed after approximately 20 miles of driving.
