Side Radiator vs Rear in Diesel Pusher

[Monkeyrun]

Wife and I have been looking for a diesel pusher in my price range for a year. The one we may purchase is a 1999 Allegro BUS39 with 76K miles and 2k hours on the genset. It is well maintained but does have some water damage below the two windows in the rear bedroom, something I can fix.

We also looked at several Dutch Star pushers, the latest one a 1998 with 56k miles and 100 hours on the genset but not as well maintained as the BUS. One big difference I see is the engine access and also the genset slides out the front on the DS. Other than that, we like the BUS over the DS, they are the same price. The DS needs six tires, the BUS will need fronts in a year or two.

My question is, how much of a factor should the additional, rear access to the engine and slide out access to the genset (in the DS) be if I am figuring that into a weighted decision between the two?

First time buyer, confused and frustrated at times but enjoying the adventure.

Thanks for any assistance you can provide!

MR

[wolfe10]

MR,

I'll get the list started.

Advantages of Side Radiator:

Easier engine access which translates to less expensive repair of things like alternator, water pump, belt changes, etc. And, even among rear radiator coaches, there is quite a wide range of service access from "top of engine". Some are easily accessed (you can climb into engine room), others have only small, difficult to access service doors under the bed/closet.

Usually a little better MPG, since the cooling fan can be set up as a two speed fan or variable speed fan. The vast majority of rear radiators are constant drive fans.

Easier to clean and less prone to clogging up.

Disadvantages of Side Radiator:

More expensive to build.

More complex mechanically [hydraulic pump and fan motor(s)]

[Monkeyrun]

Thank you Wolfe. Any opinion relative to the genset? Obviously slide out would be easier but since the hood cable broke when we were looking at the BUS I was unable to see just how good/bad the access would be to the Quite Power Diesel generator. I could see that it is housed in some kind of a box which IMHO could be an issue.

[wolfe10]

The answer to the generator question depends not only on whether it on a slide or not, but also exactly which generator it has.

Said another way, some generators have the majority of their service items accessible even when installed in a fixed location. Others have to be pulled/dropped to reach some service items.

My suggestion is to copy down the make/model of the generator and either call the generator manufacturer or look at their website for location of routine service components.

Brett

[Monkeyrun]

I am not certain that this generator does not slide out the front. We could not get the top panel of the hood open due to the cable breaking, it opened only part way, enough for me to peek inside. If you look at the front of a 1999 BUS you can see that there is another panel below the top section which leads me to believe it might slide out or at least fully open on the bottom section which would provide very good access. The salesman was of no help. I may call the previous owner.

[desertdeals69]

Usually the rear radiator is on a smaller engine such as a Cummins ISB and the side readiator is on the larger ISC or bigger.

[Monkeyrun]

This is an 8.3 Cummins, not certain about the letter designation.

[desertdeals69]

That would be an ISC 1998 or newer.

[Monkeyrun]

Thanks, did not know that desertdeals.

I am getting cold feet, seems more issues than I can imagine on these coaches. Perhaps I need to look at the Wanderlodges again, gave on them up due to none in my area that appeared road ready, yet they are at a fairly steep price.

[markstella]

I'd go with a side rad. As mentioned above, service is a lot easier. Take a look at the rear rad. and see if you can notice dirt and oil residue on the engine side of it. A lot of the older coaches didn't have the slobber tube run properly causing blow back onto the rad. making it a night mare to clean due to limited access to it. This crude has a tendency to make the engine run hot.

[desertdeals69]

I have a 32 foot with an ISB and rear radiator. I extended the slobber tube. I would not trade for a side radiator because of the engine choice. I got 10.78 mpg going between Albuquerque and Las Vegas last October. With the larger engine and coach it would be in the 6.5 to 8 mpg range. Just my own preference.

[Monkeyrun]

That much difference in mileage?

[desertdeals69]

Yes, there seems to be. Also I was towing a 1/2 ton Silverado, V6 5 speed. Unless extreme hills or headwind I have averaged between 10 and 11 mpg for the last 100,000 miles.

[RoySchoepf]

I notice that some large engine new coaches (2014) are being sold with rear radiators. We have a 40' Safari with rear radiator. We fixed the slobber tube issue when we first bought it (2001 I believe) but find that there is ongoing maintenance associated with the rear radiator location. Seems as though a lot of "stuff" is thrown up by the rear tires and the rear fan seems to grab some of it and shove it into the radiator. I find that to avoid overheating it is necessary to clean out the radiators each year!! On our coach (and I suspect on most rear radiator diesel pushers) there are three cores (engine coolant, transmission cooler and turbo intercooler). This is a very thick cooling system. These cooling systems are difficult to clean because of their thickness. The high pressure and flow that might be optimum for cleaning can bend the cooling fins. The fan shroud makes cleaning from the engine side nearly impossible. So, for what it is worth I would certainly avoid a rear radiator model were I to look for another motorhome. Yes, there is the possibility of a fan pump failure (a friend has experienced it) but what I hear from side radiator owners is that they do not have the need to clean their cooling systems often if at all - and their coaches run cool even when climbing long steep grades - I'll go for that if there is a next time!!