[arcticdude]

Tom,

It was David and his old LXi. I don't believe he changed to a rubber mounted CAC, but I do think there's something different about the DuraLite build that makes it much less prone to the failure from flexing the stock CAC's have. Something like neoprene seals on the ends that allow for some flexion without loss of pressure or something. It's been a while since I looked at that thread. He had his about 3, maybe 4 years after the replacement and had no issues with it.

[encantotom]

the question becomes one about access and room.

tom

[folivier]

I wonder if there is any one at Newell that would want to be involved in this discussion?

[bikestuff]

I am following this thread closely even though I have a kitty-Cat engine. I believe that I have the same Radiator / CAC as tom's PDF. Can someone summarize the problem that we are talking about? I thought that Tom's problem boiled down to a hose issue. And, since both of our coaches were "race" coaches they have lots of miles.

I am at Newell right now with my radiator on the ground beside the bus. In my case, the tanks on either side of the radiator are leaking under pressure. (Plan is to take rad to shop in town and see about getting tanks re-sealed) If there is a bigger problem...well lets not even discuss that since Newell does not have this rad in stock.

The techs pressurized the CAC and it was completely air-tight even though the spec calls for some leakage of air going through CAC. (thats good I think).

I would love to make the rad / CAC a little more flexible in relation to the bus.

What is not clear is the Dynamite approach of making the coils flexible with the frame of the radiator. I am really confused as to the base problem???!!!

Can anyone shed more light. (Remember to keep it simple!)

Cheers,bill

[encantotom]

bill, the problem i had was hoses. but.....the concern is that there is a lot of radiator and CAC failures in the series 60 newells and prevots and wanderlodges. all of them are side mount.

my 8v92 was a rear mount. i have not heard of any failures on it.

our guess (and others on other forums) is that since it is not mounted in any type of flexible bushing etc, that the flexing of the coach itself is enough to over time cause some issues with cracking since it is solid mounted. and there is going to be more flexing on the side than at the back.

i got a quote last year from atlas for a new radiator/cac (both of them) for 2700 but i assume that does not include shipping. back then he said he could ship in 1-2 weeks.

what i dont know is if the rad/cac on mine has ever been worked on before. i have 200k miles. couldnt tell from when we worked on it.

tom

[Richard]

Bill,

To explain the issue a little more, let me expand on Jon's insight. The radiator or charge air cooler acts a heat exchanger. The radiator exchanges the heat of the water with the air passing over it. The way it is built, and the CAC too, is imagine a bundle of straight tubes with the hot water passing through them. Air passes over the outside of the tubes. Ok, that makes sense, but how do you keep the water and the air separate? Each end of the tube is pressed into a plate with a circular hole in it. The tube is then brazed or swaged to the plate. All of the tubes are fitted into a plate at each end. When the side tanks are removed from a radiator, you can clearly see the end plates. The metals used for the tubes and end plates do not like cyclical stresses. Cyclical stresses occur each time the radiator heats and cools. The stress is even higher than just the typical thermal expansion because the outside of the radiator is constrained or hard mounted.

This raises a couple of questions. Why make the radiator tubes out of metals that are fatigue prone. One, those metals transfer heat better. Two, those metals don't rust. Three, those metals are easier to fabricate.

If you add to the thermal stress any additional stress caused by bending the radiator due to the frame it's hard mounted to flexing, then you have a recipe for failure.

By the way, when the engineers use the word stress, think an applied force.

I like this Duralite concept of free floating the tubes in a silicone grommet.

[Chester Stone]

In the whatever it is worth column, I bottomed out the back end of my coach at Dakota Ridge RV in Golden, CO. I am too ashamed to explain the circumstances. The back end skids were solidly on the tarmac, engine pan on the tarmac and drive wheel digging a hole in loose gravel. A big wrecker used two wenches to lift the rear of the coach to move it back a few inches at at time. He tied onto the frame just above the tow bar receiver. I am certain there was significant strain and stress on the frame and I was most concerned about the radiator. I have driven it 1400 miles since then and no leaks or any damage I can determine. I guess I was just lucky.

[HoosierDaddy]

Chester, It seems that you had the weight of your coach fairly evenly distributed across the back of your coach (all be it on the very rear of the frame). I wonder if the radiator/CAC is more stressed by side-to-side forces on the rear of the frame such as a heavy trailer or towd or a twisting of the rear as in one corner bottoming out.

[77newell]

I took a look at the radiator mounting in my 93 coach. The main support appears to isolated to the bottom - I couldn't see exactly how it was attached to the frame without crawling under it and I wasn't prepared to do that where it is currently sitting. The top has a square tube support running fore and aft about 8" long attached to each side of the top tank with a single bolt. This support appears to me to be for the sole purpose of limiting principally fore and aft movement of the top of the radiator. The location and length of the arm means there is some give in this support, so expansion of the radiator should not impose significant stresses on it.

The remaining question of the rear radiator mounts is if there is any "give" engineered the mounts at the bottom that carry all the weight. Someone of you may already know this but if not I'll pretty soon be crawling under to take a look at mine.

I've had a medical issue slowing me lately - this too shall pass- and I hope to find and visit a local highway bus garage.

As Red Green says: "if you can't be handsome at least be helpful".

[folivier]

I may have to either have my radiator recored or replaced since the fins are starting to corrode. Newell usually has the radiators recored since the availability for a new Atlas radiator is a few weeks.
What would you do recore for about half the price or wait for a new radiator?