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PROCEDURE FOR CLEANING REAR MOUNTED RADIATOR I have had trouble with overheating for about 10 years with my Caterpillar C-7 engine on Freightliner chassis. Several times technicians have checked, and no codes are indicated. Last year at the FMCA Convention in Gillette, WY, I again talked to the Freightliner service technicians. I explained my procedure for cleaning and was told I was doing everything correctly, but they wanted me to do two additional suggestions. 1. First: Using a 1.5-inch dia. hole saw, cut a hole in the lowest point of the fan shroud as close to the radiator as possible without hitting it. (If you do this, I suggest that you use about a 1/8-inch dia. drill bit first to create a pilot hole and then use the hole saw.) I will explain their second suggestion later. 2. My cleaning procedure. a. If necessary, remove floor at rear of motorhome to gain access to the Charge Air Cooler (CAC) and Radiator sandwich. b. In a 1.5-gal garden sprayer, mix 2 cups of Simple Green Extreme (The Simple Green Extreme will not attack aluminum.) and fill with warm water to create cleaning solution. This is very close to a 1 to 13 ratio or Simple Green Extreme to water. c. Between the fan and CAC, spray the CAC with the solution from inside the motorhome. d. Let set for about 5-10 minutes, but do not let it dry. e. Start engine and with a small nozzle on a garden hose, spray the CAC until solution is washed out the rear of the radiator. f. Turn off engine and repeat steps c, d, & e until all the solution is used. The foam exiting the rear of the radiator should be white by now. (Takes me about an hour.) g. Place a bucket under the hole you cut in fan shroud. h. From outside the motorhome using a pressure washer (1,600-1,800 psi) set to a fan spray and about 18 inches away for the radiator (You don’t want to bend the radiator fins), start at the upper left corner and work across the radiator. i. Move down and do the next section and repeat until the water collected in the bucket is clear. (I had to do mine for 3 one-hour sessions before water was clear.) Since doing the above procedure, I have traveled to several local rallies and to Arizona and back, about 4,000 miles. The highest temperature I had was on a five-mile 6% uphill grade between Phoenix and Flagstaff. The indicator was straight up on my non-numerical temperature gage. All the rest of my travel, the gage indicated about 10:00 or less. After a couple of weekend outings, I pressure wash from the outside as indicated above for about 10-15 minutes. I intend to do the steps to clean from the inside once a year before my trip to Arizona.

I have had an overheating problem for as long as I have owned my 2006 Fleetwood Expedition. I have consulted with Caterpillar, Fleetwood and Freightliner. The process I have used is to work from the inside. There isn’t very much room between the engine and fan, but I have a two gallon pump sprayer with a long wand that gets between safely. In 2 gal of warm water I add one cup Dawn and one cup Simple Green Extreme. Besure to use the Extreme because it will not cause problems with aluminum radiators. 1. I spray the radiator from the inside(have to remove floor of closet). 2. I use my garden hose with a small nozzle and spray the radiator 3. Start engine and spray with the cleaning solution. Spray with garden hose again 4. Repeat #3 until I have used all two gal of cleaner. Foam coming out the rear will be white. Usually takes me about an hour. 5. Spray with garden hose until all foam is gone. The above are the steps I have used for 14 years on my coachs once or twice a year. At the FMCA Gillette Convention, I consulted with Freightliner again. There rep said that was very good, but he wanted me to do two more things. 1. Before starting to clean use a 1 1/2 inch hole saw and put hole in bottom of fan shroud being careful to not hit radiator. He stated that the dirt collects there and when dry will clog radiator again 2. Clean as I have done in the past. 3. From the outside use a pressure washer using the fan nozzle about a foot or more from the radiator. Caution don’t use so much pressure that you bend radiator fins. Start in upper left corner and move to center. Go to upper right corner moving to center. Continue down the radiator until water that drips out the bottom is clear i have had to make many passes, but I have found that there is a great amount of black dirt does come out using the pressure washer. 4. After dry cover hole that was cut in fan shroud with extreme tape to prevent turbulence. I won’t be able to drive far enough away for a few weeks to test to see if this is the solution, but a lit more dirt has come out.

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