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Old 05-11-2015, 09:16 PM   #15
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Old 05-12-2015, 09:11 PM   #16
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A very good discussion indeed. However I do notice that the side radiator advocates never mention the dedicated hydraulic system that is needed to run the fan in those units. Not a deal breaker either but shows that there are always tradeoffs. In our side rad coach Tiffin had to install a baffle to keep hot air from recycling back through the radiator and causing heating problems. That happened before we owned it and it has been excellent for us.

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Old 05-12-2015, 10:15 PM   #17
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I find it amazing that rear radiator coaches were made for many years, then technology for the side radiator came around. The cooling on our rear radiator coach has been just fine and like other I clean it annually.

We had our belts changed about 5 years ago and all is well. IMHO I would not state that either type of radiator is a deal breaker if I like the floor plan. Remember that there are MANY coaches with a rear radiator still on the road and they run just fine. This would not be enough to sway my opinion on whether or not to buy a specific coach.

Things to look for that REALLY can cause problems are chassis related. Do your research on each model you look at to see if there are known issues with chassis weakness, poor steering, etc. Just my opinion but there are other more important things to worry about than where the radiator is located. Good luck in your search!
2001 Holiday Rambler Endeavor
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Old 05-12-2015, 10:22 PM   #18
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It seems the rear radiators are usually on the coaches with smaller engines. My MH has the Cummins ISB engine, lots of room around the engine. Everything is still visible and accessible from under or above. Routine belt changes occur once every 5-7 years. 1st time the serpentine belt took me at least an hour, DIY. Now I can change both belts in about 20 minutes.

Agree that a floor plan that suits your needs is more important the the location of the radiator.

Cleaning the radiator is not a problem if it is done routinely. I spray mine from both sides with Simple Green Heavy Duty (safe for aluminum) and rinse from both sides. Never overheated.
Hooligan, Pensacola, Fl -U.S. Coast Guard 1956-1985
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Old 05-12-2015, 11:11 PM   #19
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I had a rear radiator Diplomat for almost 10 years and it wasn't a really big deal. It's important to note that most chassis' sandwich their radiator and charge air cooler, one in front of the other. On Monaco coaches, they are stacked, one on top of the other. They cool better and are easier to clean.

Most coaches come with a rear radiator to about the mid level price. 400 HP (ISL) is the biggest engine I've seen in a rear radiator.

I'm a DIY guy and when I decided to get a new coach, a side radiator was in the must haves, primarily because I was buying a bigger, heavier coach. Rear radiator coaches draw somewhere around 25 HP to run the fan. Side radiator coaches draw somewhere around 40 HP to run the hydraulic fan.
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Old 05-14-2015, 08:05 AM   #20
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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.

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Old 05-14-2015, 10:39 AM   #21
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Originally Posted by DebnDan View Post
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.

2004 ITASCA HORIZON 36GD, 2011 GMC Sierra 1500 4x4 Toad '08 GL 1800 Gold Wing
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