Cleaning DP rear radiator

[jetfromtn]

What is the best cleaner and method to clean a rear radiator without drenching everything on the backside?

[azloafer]

Almost all of the posts that I have read say that Simple Green should be sprayed onto the radiator and allowed to sit for a few minutes before spraying off. I haven't had this coach long enough to try it. Joe

[Chief]

I use "Simple Green" applied with a garden type sprayer. Apply the properly diluted mix from the inside/underside of the engine. Be sure to apply on the front side of the turbo cooler and the radiator, let soak and hose off with standard garden hose (finger pressure only). No overheating problems in 5 years.

If the engine/radiator is very dirty I suppose you could apply the product to the front (forward facing) side of the turbo, then start the enging temporarily to help distribute the cleaner using the engine fan.

[GaryKD]

Hi jetfromtn,
All I have ever use is compressed air. I have a an air compressor with 150 PSI at the nozzle. It takes a couple of hours for me to get through the entire radiator. I go slow and make sure I get every row of cooling fins. I place a pipe cleaner at the end of the row I just completed to mark my progress. When the compressor kicks off, I stop and wait for the pressure to build. Lastly, I run a long pipe cleaner through selected rows (near the bottom) to check if there are any clogs.

[mahon1993]

I use the Simple Green cleaning method and it works great. One other note, it's a good idea to take a good hard look at your rear radiator from the engine side. Somewhere along the way I must of ran over a plastic market bag. It was shreaded from hitting the fan but plastered on the inside of the radiator.
Greg

[1ciderdog]

If yours is like mine there are two "radiators" back there. The one closest to the engine is the charge air cooler. Mine was very dirty - the previous owner had not modified the crankcase vent so oil vapor had been accumulating on the radiators for quite a while and I live down a dirt road so it didn't take long to mess up the air flow. I used simple green but there are members that give warnings that simple green is hard on aluminum. I also tried Dawn as some members recommend. I sprayed simple green into the radiator from the back side using a garden sprayer and then rinsed it as best I could then did the same from underneath the engine. I moved the fan blade so I could spray more of the air cooler. I ended up doing this on two occasions and may do it a third time as I'm sill getting above 200 on some hills but it runs much cooler than before. Be prepared to use lots of water to rinse the soap out. The second time I cleaned the radiator I used simple green then rinsed then washing it again with Dawn. I'm glad I live very rural because I used to much Dawn. After washing and rinsing I started the engine and watched bubbles blow out for quite awhile. I ended up tying the garden hose under the engine very close to the fan and letting the water run while the engine idled. The fan pushed the water and dirt on through both radiators. NOW THAT'S A REAL BUBBLE MACHINE!! Kind of good because I could easily tell where air was easily flowing through the radiator by the amount of bubbles. I did have a concern I might push dirt further into the radiator fins rather than through the fins. I think you do need to be a bit cautious about using to much pressure and bending the fins.

[majfrizz]

when i attended Camp Freightliner. they suggested spraying with Simple green, let sit for a few minutes, then crank her up. just watch out behind on what all is sprayed out.

[chasfm11]

,,,and whatever you do, DO NOT use a pressure washer. Garden hose pressure is enough.

On most rear engine radiators, the place that gets clogged first is the perimeter - outside the fan path. You should be able to shine a flashlight in from the rear and see what it looks like. Of course, getting the Simple Green sprayed into that area (it should be applied from the engine side into the Charge Air Cooler (CAC) can require standing on your head. The best suggestion I've heard is to get a garden sprayer and mix the Simple Green from concentrate in that. Obviously, you don't want to try doing that with the fan spinning.

When I did mine the first time, it was so dirty (we bought used) that it took two cycles to get the gunk out. After that, I do it a couple of times a year and it cleans up just fine with just one spray on, rinse off cycle.

[grampakoot]

I have done a thorough cleaning with dawn and garden sprayer as suggested.
wolfe10 has posted a thorough procedure which I followed.
I thought I had solved my problem but my first 300 mile trip after the wash showed I still have a huge problem.
I seem to be able to run for 100 miles or so and if I try to cruise and get a bit of an incline whereby the rpms drop below 1500 my heat rapidly rises and no matter what I do after that I can't get it back down.
Once the temp gauge needle get to the red mark...no matter what I gear down to it insists on staying there...even after stopping for an hour and resuming. I am however able to keep it from exceeding too far past the red mark by staying above 1800 rpms.
I had the radiator caps replaced last winter. I'm tempted to do that again in case they are faulty.
Your thoughts please.

[TQ60]

Check the operation of your fan, second check the water flow.

Get a non-contact thermometer, with this you can measure the different parts of the radiator to insure all of it is working, a cool spot is blocked.

[1ciderdog]

Grampakoot - FYI - It took me two very through cleanings of my rear air cooler & radiator to get it so that the engine temp didn't go wild on hills. Maybe you need to do it again. I used simple green the first time with a good rinse and then after the next trip I wasn't satisfied so I did it again with simple green, rinsed then used Dawn & rinsed. That seems to have done the job. I also lengthened the crankcase vent so it would no longer feed into the radiators.

[two-niner]

It could be your thermostat.

Kerry

[Hooligan]

Mahon: The plastic bag is not unusual----Returning this week from Michigan, passed over a plastic bag, did not see it emerge behind me. Engine temps did not change but checked at the campground later and picked parts of the shredded bag from CAC.

[Catch and Release]

Attended Camp Freightliner this week and Mike Cody talked about the issues of using Simple Green on aluminum. There is a new product called Simple Green Pro HD that is the recommended cleaner for radiators. It is purple in color.