Originally Posted by DebnDan
I am fairly new to the diesels. Can someone please explain exactly what is done to clean the rear radiators. Is there a solution you spray on that get the crud out and then just rinse with a garden hose? I assume scrubbing and or power washing is a bad idea.
Dan Callahan, North Jersey
2008 Fleetwood Excursion 40E
Freightliner, Cummins, Allison
It's not the Destination or the Journey
It's the Excursion
As you may or may not know, some rear radiatored coaches, especially one's equipped with the CAT engines, had/have an issue with "Blow-by" mist getting into and on, both the CAC and the radiator. When that happens, it's basically an oily film and of course, the fan and, road speed (tires participating too) kick up a ton of dust and debris.
And, because of the direction of the air movement from the fan, that dust and debris is deposited into and on, the fins of both units. Well, when not maintenanced, that dust/debris/oil film will build to the point that, no air will pass through and we all know what happens next, OVERHEATING!
So, the VERY FIRST THING that should be done, especially on the CAT equipped coaches, is to lengthen the Blow-by tube, (which normally exits right next to the oil pan, about half way the length of the engine, to a point that the blow-by gases are dispensed at or beyond the rear of the coach and therefore, not deposited onto or in, the fins of the CAC and radiator.
Now, cleaning the radiator to rid it and the CAC of all of the deposits and grime, on some coaches, is easier than others. But, for the most part, on the majority of the coaches out there, it's one serious pain in the a$$ to get them REALLY clean. The main reason is ACCESS to those fins. I will not speak for anyone's but mine. The coach is an '04 Itasca Horizon, 36GD with the C-7 330HP CAT. The way the fan shroud is designed, the heat exchanger for trans cooling, other structure, tubes, and more are laid out under and around the bottom of that coach, it is COMPLETELY IMPOSSIBLE for any effort at all, to even get anywhere near those fins to clean them.
Some folks, have opted to either lift the bed, or, remove it, then cut an access hole in the top of the fan shroud to gain better access to those two components for cleaning and, doing other maintenance. It's not a bad idea but, knowing what I know and, having done quite a bit of maintenance/repairs etc. to the radiator and related components of the area, I would pull that radiator and CAC to THOROUGHLY clean them both. There are other folks that done the same.
It by far, is not an easy chore. The first time it took me close to 6 hours to get both of them out. But, knowing what I know now, I could do it in about 1/2 that time, or less. But, two things. One, this is ME, and I know what's needed to thoroughly clean both. Two, I've since moved my blow-by tube and extended it all the way past the rear body and, will NEVER have that oily mess in my fins again.
Yep, I might get some of the dust etc. but, not the oily goo that was built up on both for quite a few miles before I got to it. And three, and this is really important, have the EXACT CORRECT amount of oil in that engine. Too much and you get some of it, spitting out the blow-by tube.
Now, as for using a pressure washer, the worry warts will run and hide when this is mentioned. When I removed my radiator and CAC for some repairs and maintenance, they both were really gooed up with years and miles of blow-by and debris. I purchased some high strength ZEP citrus based degreaser. I laid that radiator on its side and, using a big quart sprayer, thoroughly soaked the fins of it. Well it took three times of that before the goo started to drip out the other side of the fins.
At that point, I broke out the 2600 psi pressure washer. I ran the wand of that pressure washer over those fins, from about 3" away and, blew out some of the ugliest stuff I'd ever seen. OF COURSE I WAS PAYING ATTENTION to the fins, to make sure there no damage was occurring to them from the pressure of the wand.
Absolutely none, had occurred. Those fins were as straight and perfect when I was done, as they were when I started.
But, doing this job, in MY COACH, while the radiator and CAC are in place, again, IS IMPOSSIBLE to do a thorough job. There's simply way too much components/hoses/shrouding/frame/ and more, in the way.
Other folks have reported good results from their methods of cleaning those, either from underneath or, the access hole in the shroud or, by other means and access. I'm envious of them. But, the main thing is, to do it on a somewhat regular basis, after it's been initially done, to keep everything free and clear of road debris/dust and whatnot.
Most guys use some form of Aluminum safe 409 and, home built bent garden hose nozzles. One thing is for sure, you need an area that you won't mind making a serious mess on and, you also will make a mess out of YOURSELF. Good luck.