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rossboyer

CLEANING REAR RADIATOR-FREIGHTLINER CHASSIS

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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.

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Had similar overheating issues with my Winnebago on a Frieghtliner chassis with a Cummins engine. Mentioned it to the Frieghtliner service manager in Rapid City while having other work done. They sent me to a local truck wash and they power washed the radiator until the waste water ran clean.  Apparently they do this a lot. $15 dollars and a half hour later my overheating problems were solved. The service manager recommended having this procedure done every couple of years. They were very careful to stand back far enough with the pressure washer as to not cause any damage.

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You also need to clean from the engine side to clean the cac and transmission coolers. Be sure to use Simple Green Extreme which will not harm the aluminum radiator core. 

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dspalding1, Welcome to the forum.

Yes using Simple Green Extreme is the preferred way. I have found driving through 10" per hour rain storms will do a amazing job of cleaning the CAC and radiator. The CR-V was covered in crud including the little chunks of oil/dirt from between/ in the radiator fins and CAC. If I had known I was going to run into that much rain I may have sprayed the CAC and radiator in advance. 

There was so much water spray coming through the radiator it looked like the car was in a wind tunnel.

Other than that a annuel (minimum) cleaning and learning how to manually downshift will keep your coach running cool.

Bill

 

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Doing so was the time I got the whole sandwich of heat exchangers clogged the worst. The roadway had been coated with a chemical to prevent freezing. Packed in like mortar. 

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I think this is my issue.  The rig runs beautifully and cool on flatter terrain but when I hit just the slightest grade, I'll watch it come up.  Yesterday, I was stuck keeping the engine at 2500rpm min and 25-30mph going up a 4mi 6% grade to keep it from overheating.  I was the slowest guy around but had plenty of power otherwise.  

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My Cummins ISL 400hp was overheating on hills, radiator/cc were clean, turned out, fan clutch was faulty and not kicking into high, had a Freightliner shop replace and I'm makin' ice cubes now even on hills! 

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22 hours ago, manholt said:

Even so, I hope you take Brett's advice...I have experienced both sides of that issue!

Oh for sure! Got to keep that radiator and cc clean or all the air in the world will not keep 'er cool! 

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