timnjulie Report post Posted August 17, 2021 I was told by Cummins dealer my 300 Cummins rear engine Charge Air Cooler on my 2005 Thor Damon Astoria class A motorhome was completely plugged. Where exactly is it located? Is it the big radiator when I open the rear engine hood? Or is it on the other side between the radiator and engine? I would like to clean it myself to save some money. Tim Share this post Link to post Share on other sites
wildebill308 Report post Posted August 18, 2021 (edited) 1 hour ago, timnjulie said: Where exactly is it located? Is it the big radiator when I open the rear engine hood? Or is it on the other side between the radiator and engine? I would like to clean it myself to save some money. It is in front of the big radiator. I would check between the two as they get full of crud. especially between them. Yes you can clean it your self. I recommend simple green. Spray it down well let it soak for a little while and rinse it out with a garden hose till the water runs clear then repeat at least once. Don't use a hard stream or you can damage the fins on the radiator. Use a light to make shure you can see light through the radiator and charge air cooler. Let us know what you find. Bill Edited August 18, 2021 by wildebill308 Share this post Link to post Share on other sites
timnjulie Report post Posted August 18, 2021 Thank you! I thought that was what you do but wanted to be sure. I cleaned it once this year from the engine side, sprayed simple green behind the blades. Then rinsed after 15 minutes. So if I’m over the engine, facing the rear, I need to clean the fins just behind the fan blades? Correct? Share this post Link to post Share on other sites
elkhartjim Report post Posted August 18, 2021 If it is truly plugged, it would probably be better to remove the radiator and the CAC and have it professionally steam cleaned. Should you decide to undertake the project yourself I suggest using the Simple Green that is formulated for aluminum or limit the time the Simple Green Heavy Duty Cleaner is on the aluminum to no more than 10 Minutes. I used a pump up sprayer with the correct mixture of SG and water and sprayed from the engine side. Let it set and rinse with a garden hose. If its plugged its may take several applications. Share this post Link to post Share on other sites
elkhartjim Report post Posted August 18, 2021 I just saw your second post. You need to clean more than just behind the blades. You need to clean as much as possible. Make sure to check for plastic bags, etc. Share this post Link to post Share on other sites
wildebill308 Report post Posted August 18, 2021 13 minutes ago, timnjulie said: I need to clean the fins just behind the fan blades? Correct? That is a start. You need to clean the front of the radiator to and make shure "like Jim said" that there is no trash between the CAC and radiator. Unless you have had a oil leak on your turbo you only need to clean the outside. There must be 100 videos on you tube about it. Bill Share this post Link to post Share on other sites
timnjulie Report post Posted August 18, 2021 Thank you Share this post Link to post Share on other sites
manholt Report post Posted August 18, 2021 On main Forum page, type in search box...how to clean CAC. Share this post Link to post Share on other sites
somewhereinusa Report post Posted August 20, 2021 Just curious, if the CAC is completely plugged, why is the engine not overheating? The air that cools the engine passes through the CAC. Share this post Link to post Share on other sites
rossboyer Report post Posted August 20, 2021 The Simple Green referenced above should be Simple Green Extreme using a 1/13 green to water if I remember correctly. The label explains the ratios to use. Share this post Link to post Share on other sites
wildebill308 Report post Posted August 20, 2021 1 hour ago, somewhereinusa said: Just curious, if the CAC is completely plugged, why is the engine not overheating? The air that cools the engine passes through the CAC. Did you miss that this was a dealer telling him this. As in if you don't pay us $$$$ to pull it and clean it you may not get home. Bill Share this post Link to post Share on other sites
rossboyer Report post Posted August 20, 2021 Search for my post dated May 22, 2019 Procedure For Cleaning Rear Mounted Radiator. It is lengthy re-post. My MH has a CAT engine, but the process is the same for you. Share this post Link to post Share on other sites
rayin Report post Posted August 20, 2021 (edited) This is referred to as the radiator sandwich because it can contain as many as 5 cooling- radiators; engine coolant, charged-air cooling radiator, transmission cooling radiator, hydraulic oil cooling radiator, (and if separate) power steering cooling radiator. Between these radiators exists approx. a 1" gap that easily collects leaves and oil droplets from the engine collect dirt and road grime. Edited August 20, 2021 by rayin Share this post Link to post Share on other sites
timnjulie Report post Posted August 21, 2021 Thank you all for your response, I am going to start on this I appreciate all your help. Tim Share this post Link to post Share on other sites
jleamont Report post Posted August 21, 2021 Here is one topic on this subject; Share this post Link to post Share on other sites