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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 a 2001 American Eagle 40 foot with a Cummins 350 that weights 33k. I tow a Grand Cherokee that weighs 8k. I am told that I need and estimated 10 horse for every 10k of weight so I am somewhat under powered. I have had my radiator fins pressure cleaned, the cooling system flushed and pressure tested and the fans tested to make sure they are kicking on and running at the appropriate time/temp. Additionally I have changed out the thermostat to make sure it is not sticking or causing flow issues. On hill climbs in Colorado, Arizona and Nevada I will constantly overheat and have to pull over to cool. I use the Alison mode to run between 2200 and 2400rpm during climbs to increase circulation but eventually my alarm kicks off. I never heat to critical levels but alarms start at about 190 or 200, normal running temp for this coach is 160-170. My temp gauge goes up to 240 but I never heat more than 200-210 but I don't like running that hot and the alarm is distracting. Besides the climbs, I saw last week this heating on flats in Nevada. Of course the outside temp was 100 but I would not have expected overheating on flats. Now in the fall and winter months most climbs and all flats don't cause overheating due to the cooler air. The engine is well kept, has about 75k on it and fluid and filters are constantly maintained. Now what is very strange is that I lose about 1/3 gallon of coolant every 400-500 miles. It does not drip out as I have zero leaks under the coach. It is not making it's way into the engine as engine fluids show absolutely no signs of moisture. I have had the system pressure tested 3 times to make sure I don't have a high temp hiss/steam leak and the reservoir tubes and cap are not leaking. My questions are as follows. 1. Does this just sound like a HP issue and that the 350 just can't handle the 41k pounds of coach and toad? 2. Any ideas where the coolant may be going? Some have suggested it may be leaking into the turbo but that makes no sense to me 3. Does anyone know of an after market turbo monitor gauge so I can monitor that with RPM? 4. Are there any after market cooling systems that can be put on to help with the overheating or do I just need to buy a new coach with a larger engine? Thanks for reading!

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.

I need to replace the radiator in my 2005 Monaco Signature. The engine is an ISX 525 Cummins. I have 3 questions. 1. Does anyone know the part number for the replacement radiator? 2. How labor intensive/complicated is the replacement process? 3. Does it require any special equipment? Thanks in advance!

Had radiator issues on my Cummins engine while traveling through Kingsville, TX. Found Acme Radiator & Muffler shop in town. Small place but great service. Carlos got right on the issue and had me back on the road as fast as could be expected. I thought I would have to have the radiator pulled but Carlos said no and fixed it with new hoses. Honest service and reasonable prices. A big truck shop would have spent much longer and lots more money. Carlos said he could work on any size unit. If you have a problem while in his area I would recommend him.

I thought you might benefit from this. It might save you a gob of money, in the long run. After friends sent their Discovery in for radiator service and ended up with a huge bill, I starting getting more serious about tending to mine*. Bear in mind the buddy who owned mine prior to our purchase periodically raised the closet floor and shot degreaser onto the engine and radiator, and I've done the same every six months or so in nearly two years of steady use. We had been overheating, but only under extreme conditions, eg making 2-mile constant climb at 60 mph in N. Arkansas with 100+F ambient temps (120+ against the pavement). Even then, a short downhill run with the exhaust brake on to boost rpms, or pulling over resulted in immediate return to normal. A recent trip to Galveston resulted in perfect temps, albeit with 85F outside. Still, after the trip, I applied degreaser to the aft side of the radiator, waiting 20 minutes, shot the fins with a safe blast from the hose. What looked like mouse turds showed up in the driveway. Lil' greasy mouse turds that turned into a smudge when rolled between my fingers, rather than the wholesome, nutty but slightly gritty goodness of the real thing... Clearly, the engine side of the radiator was a muffin mold of sorts for these little pellets. Using the heavy duty degreaser in a spray bottle, I hit it from the back side -- the idea was it'd pass through to the engine side -- another five or so times, waiting and rinsing each time. The next morning, I jammed a digital camera up inside the shroud and shot a series of photos. One spot on the lower right was gummed up solid, despite repeated cleaning. So, I got a gallon sprayer and loaded a 1:4 mix of the Simple Green Pro HD from Home Depot yesterday, rated safe for aluminum, sprayed the engine side of the radiator while hot, let it sit for 20 minutes and then rinsed. There was quite a difference, althought further cleaning was needed. As a result of this discovery, I'm programming a misting of degreaser up under the shroud on the engine side, after every trip. It only takes a minute or two, can be paired up with hooking up the black tank rinse, done at the same interval. Thanks for the comments below. Indeed, the moral to the story was that degreaser must always be applied to both sides of the radiator, with an emphasis on the upwind eg front side. Use good judgement to protect the delicate fins: some pressure waters have "Delicate" tips and are appropriate; if in doubt, use a hose-end sprayer.

I have two small leaks in the radiator of my 2000 American Tradition, found during a service inspection. No overheating, no leaking on the ground. Cummins dealer says replace the radiator but wondering if some sort of stop leak product is safe to use and would work. Starting on a long trip.