Side or rear radiator diesel pusher

John S. wrote:
A big issue is if you need service. Cummins told me they will only schedule in one rear mount a week but on side mounts there is no issue as you do not have to pull the radiators to work in them. That being said, they also said the trend with the bathroom above the engine on some newer coaches means that some simple jobs be one much more costly s they will have to drop the engine then work in it and then reattach adding 16 hours of labor.

Now THAT is some interesting information! No engine access from above if you have a rear bathroom???

Some bad information is being posted here. Information from people that do not have any mechanical knowledge. When somebody posted that the engine has to be dropped to work on it, that to me is a person that has just driven the coach but has no know how on how to fix these engines.

I had a exhaust manifold replaced on my Caterpillar 3126-E at Freight liner and they done it with no problem without dropping the engine.

When my coach was new I had the valve lash adjusted at so many miles and they just lifted the coach on a hydraulic lift and worked from underneath the coach with no problems.

Then some more wrong information that a coach with a rear radiator sucks air in? Coaches with rear radiators suck the hot air from within the engine box through the radiator and CAC and gets rid of the heat.

Then the post about only coaches with tag axles have side radiators. Again wrong information I have seen many commercial buses with rear radiators, side radiators and center radiators. The chassis builders will place them in different places.

The do cost a lot more because of hydraulic pumps and hoses that have to be added. And the statement that they never give problems is a laughable statement. They are mechanical and anything mechanical can give problems.

I have never had any problems with my rear radiator through 13 years. So to me even if I was to buy another coach it would not be a deal breaker. To me the most important thing in purchasing a coach is the floor plan.

A big issue is if you need service. Cummins told me they will only schedule in one rear mount a week but on side mounts there is no issue as you do not have to pull the radiators to work in them. That being said, they also said the trend with the bathroom above the engine on some newer coaches means that some simple jobs be one much more costly s they will have to drop the engine then work in it and then reattach adding 16 hours of labor.

RayChez wrote:
About the only advantage is to get to the engine to change the belts. Other then that there is really not that much of the engine exposed to do anything else.
Side radiators do take some horse power off the engine because they are hydraulic. Also side radiators do take up where a valuable compartment could be (especially)for full timers. And side radiators are right behind the rear wheels where debris will be kicked back and could damage your radiator.

Rear radiators about 15 years ago had a problem with both Cat and Cummins engines with a slobber tube that was not extended long enough and oil condensation or just over filled crank cases would throw the oil out the breather tube and into the radiator causing radiators to plug up and engines would overheat. Problem was solved with the Cat engines by extending the breather tube and cutting the amount of oil from 24 quarts to 19 quarts.
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I bet you have a rear radiator!

The side radiator is so much easier to visibly inspect the engine for coolant leaks, oil seepage, etc. It is so much easier to just pop open the rear engine cover and look for anything unusual in the engine compartment. I doubt very many people open up the hatch in the bedroom to inspect the engine daily like I do with a side radiator.

So many things are easier to replace on a side radiator such as alternator, coolant hoses, belts, exhaust manifold, fuel pump, fuel and coolant filters, etc. on a coach with a side radiator. Ask any mechanic.

As was said in other posts, all the road debris and dirt from the rear wheels is kicked up directly into a rear radiator, not so with a side radiator. Most of the posts you read on here about overheating problems are with a rear radiator for obvious reasons.

One of the reasons is that a side radiator is drawing cool outside air into it. A rear radiator draws hot engine air directly into it.

The extra expense for a side radiator is well worth it and for obvious reasons.
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On the Cummins engine the extension of the tube solved their problem.

Side radiator coaches did not have that problem with oil getting on it.

Side radiator coaches usually cost more because of the hydraulic pumps they have to add.

They both work good once the modifications are made and both have to get a cleaning with a cleaner and water every so often especially if you drive much on dirt roads.

This was not necessary on side radiators as was stated.

There's a little more to the difference between a rear and side radiator. Larger engines/coaches require more cooling and a rear radiator will not do the job. Typically, the largest engine you see with a rear radiator is the 400/450 ISL. I doubt you'll find a Cummins ISM or ISX with a rear radiator. The tipping point seems to be the ISL.

I previously owned a rear radiator Monaco Diplomat and it always performed well. When I looked for my next coach, I wanted a side radiator because it was a larger heavier coach, I do my own service and often, many builders move to the engine brake in combination with the side radiator.

Monaco's Roadmaster Chassis stacked the Charge Air Cooler (CAC) above the rear radiator, where everyone else was/is stacking them one in front of the other. The Monaco design was the best, since you could get to the front and back of the CAC and radiator without a lot of effort. The other brands made/make it a nightmare to clean between the sandwiched units. No matter if they have a slobber tube or not, you'll have to get in there and clean between the two at some point.

I think anyone looking in a price range where the majority of the coaches come with a rear radiator, I wouldn't let a rear radiator be a deal breaker.

Like "Executive", my rear radiator worked well, but my next coach had to have a side radiator, tag axle and engine brake.....just my preference after owning a rear radiator DP for nine years.

Side is much cleaner. We've traveled many gravel roads as we love to boondock. Never had a problem.

Side radiator are far less troublesome than the rear radiators, possibly because the manufacturers may have used a less expensive radiator core to save money. Several of our friends with rear radiators have had to have them rodded out or repaired, while none of our friends with side radiators have had problems. Our coach is a 1993 with a side radiator and it has never had any problems.

Side radiator is cooled down by fresh air, while rear radiator is cooled down by whatever comes from engine bay.
Engine heat, oil leaks, coolant leaks

About the only advantage is to get to the engine to change the belts. Other then that there is really not that much of the engine exposed to do anything else.
Side radiators do take some horse power off the engine because they are hydraulic. Also side radiators do take up where a valuable compartment could be (especially)for full timers. And side radiators are right behind the rear wheels where debris will be kicked back and could damage your radiator.

Rear radiators about 15 years ago had a problem with both Cat and Cummins engines with a slobber tube that was not extended long enough and oil condensation or just over filled crank cases would throw the oil out the breather tube and into the radiator causing radiators to plug up and engines would overheat. Problem was solved with the Cat engines by extending the breather tube and cutting the amount of oil from 24 quarts to 19 quarts.

On the Cummins engine the extension of the tube solved their problem.

Side radiator coaches did not have that problem with oil getting on it.

Side radiator coaches usually cost more because of the hydraulic pumps they have to add.

They both work good once the modifications are made and both have to get a cleaning with a cleaner and water every so often especially if you drive much on dirt roads.

Choosing a coach with a side radiator will likely leave you a little lighter in the check book. That's the only down side.