Check your air cooler

Topic: Check your air cooler (Read 772 times) previous topic - next topic

Check your air cooler

April 03, 2016, 02:14:53 pm

While I was doing the 303 on the decals last week I looked through the radiator grill REAL close and realized I had a problem. Air cooler (for lack of the proper term) was loose. Removed the grill and found the air radiator was held on by the rubber shroud ( loosely) ) and one cracked tab, instead of 4 ! To the point that it was leaning against the coach frame. Could have worn a hole in it, but hadn't yet.

Troublesome to me because how would I have known if it began sucking dirty air in. Fixed now.

Re: Check your air cooler

Reply #1 – April 03, 2016, 02:18:48 pm

Good documentation.

Yes, it is called (by various manufacturers): CAC (Charge Air Cooler), Inter-cooler, After-cooler.

And, I would not worry about it allowing dirt into the engine. It is under pressure (from the turbo), so the symptom of a leak would be loss of boost pressure and therefore loss of power. Said another way, the air would leak OUT, not in.

Intake air flow to your engine is as follows: air filter, turbo, CAC, intake manifold.

Re: Check your air cooler

Reply #2 – April 03, 2016, 02:33:13 pm

So, the engine is always under a air boost ? Even at low rpm ?

Re: Check your air cooler

Reply #3 – April 03, 2016, 02:35:15 pm

I would worry about dirt getting in. It is kind of unbelievabe but I have seen it firsthand. A fitting came loose on turbo plumbing in a car of mine. Boost leak, power loss, all that, but when we pulled the plumbing apart we could see dust lining the inside of the plumbing, coming from the leaky area. This was on the way to the intercooler with many PSI boost pushing that dirt in the opposite direction but it got in anyway. Downhill and between shifts, all I can figure is that there is a fair bit of vacuum in the circuit at those times...Brett knows more than I do regarding diesels since I am a newb with them. It may be that there is positive manifold pressure at all times in a diesel. Our coach's boost guage doesn't have a negative scale so I don't kow for sure.

Re: Check your air cooler

Reply #4 – April 03, 2016, 02:40:20 pm

Jay,

Was this on a turbo gasoline vehicle (i.e. throttle plate so vacuum at idle) or turbo diesel. If turbo diesel did it have a throttle plate?

Large diesels (both Cat and Cummins and certainly 2 stroke DD's) can not create "vacuum" on the intake side-- they have no throttle plate.

Re: Check your air cooler

Reply #5 – April 03, 2016, 02:42:10 pm

Quote from: mike leary – April 03, 2016, 02:40:03 pm

When did inter-coolers become "ne plus ultra" on our coaches? Was it a design change or a special order? I've sure heard good things about those.

Sorry, Mike, not sure I understand the question.

Re: Check your air cooler

Reply #6 – April 03, 2016, 02:50:31 pm

Quote from: wolfe10 – April 03, 2016, 02:42:10 pm

Sorry, Mike, not sure I understand the question.

Sorry, Brett. The question is: do we all have some sort of inter-cooling, no matter what age? I recall Volvo sure hyped it.

Re: Check your air cooler

Reply #7 – April 03, 2016, 02:58:11 pm

Mike,

Yours certainly does. Not familiar enough with really ancient history to know when they were first used on Fortravels. Could have been from the beginning-- I really don't know. Could also have depended on engine.

But, a very good idea with any turbo diesel. Cool, dense air is better for MPG and HP than hot air. And, air on the intake side coming out of the turbo can be over 300 degrees F. The CAC cools it (just an air to air radiator) back to close to ambient temperature.

Re: Check your air cooler

Reply #8 – April 03, 2016, 03:00:05 pm

Quote from: wolfe10 – April 03, 2016, 02:58:11 pm

Mike,

Yours certainly does. Not familiar enough with really ancient history to know when they were first used on Fortravels. Could have been from the beginning-- I really don't know. Could also have depended on engine.

My 1981 with the 555 Cummins only has turbo no CAC or inner cooler

Re: Check your air cooler

Reply #9 – April 03, 2016, 03:15:55 pm

Quote from: craneman – April 03, 2016, 03:00:05 pm

My 1981 with the 555 Cummins only has turbo no CAC or inner cooler

That's been a source of my questions for a while : " When did FT go to side-mounted radiators and when did they go to CAC?" I'm thinking '92/'93. So WHY is Bob's CAC (a '95) stuffed into the stern?
I'm thinking, that each one of these dears, with different engine configurations, were built VERY differently.

Re: Check your air cooler

Reply #10 – April 03, 2016, 03:22:25 pm

Quote from: mike leary – April 03, 2016, 03:15:55 pm

That's been sorts of my questions for a while : " When did FT go to side-mounted radiators and when did they go to CAC?" I'm thinking '92/'93. Michelle, where are you?

My 1981 is a side mounted radiator

Re: Check your air cooler

Reply #11 – April 03, 2016, 03:35:19 pm

Quote from: craneman – April 03, 2016, 03:22:25 pm

My 1981 is a side mounted radiator

Other than your ultrarare Hendrickson chassis the next side radiator was the 87 300hp 3208 CAT with its ATTAC. air to air after cooled engine

Re: Check your air cooler

Reply #12 – April 03, 2016, 03:59:31 pm

Nice fab job on the mount. Aluminum can be hard to get clean enough for a good weld

Re: Check your air cooler

Reply #13 – April 03, 2016, 07:50:45 pm

I had to replace mine as the mount broke and peeled back the core at the same time.

Re: Check your air cooler

Reply #14 – April 04, 2016, 05:20:44 am

Quote from: its toby – April 03, 2016, 03:59:31 pm

Nice fab job on the mount. Aluminum can be hard to get clean enough for a good weld

Thanks.
A friend did the fab work. He works on high dollar "one of a kind" autos. I wanted a quick turn around so he knocked it out quick. Doesn't do ANYTHING half xxxxx. He also told me to mount it using urethane bushings cause of the vibration.

Re: Check your air cooler

Reply #15 – April 04, 2016, 10:04:12 am

@Mike, Brett,

I have yet to see a DD 6v92 with the CAC.

see ya
ken

Re: Check your air cooler

Reply #16 – April 04, 2016, 10:16:16 am

Quote from: kenhat – April 04, 2016, 10:04:12 am

@Mike, Brett,

I have yet to see a DD 6v92 with the CAC.

see ya
ken

Yup, built into your engine, not separate unit. Just google "Detroit Diesel 6V92 after-cooler" or Detroit Diesel 6V92 inter-cooler"

Re: Check your air cooler

Reply #17 – April 04, 2016, 10:20:01 am

Quote from: wolfe10 – April 04, 2016, 10:16:16 am

Yup, built into your engine, not separate unit.

Ahh, is that why I can't see mine, as well?

Re: Check your air cooler

Reply #18 – April 04, 2016, 10:31:15 am

Quote from: mike leary – April 04, 2016, 10:20:01 am

Ahh, is that why I can't see mine, as well?

NO, yours is external. Follow the large diameter tubing from turbo to CAC and from CAC to intake manifold. It is in front of/outboard of the radiator.

Re: Check your air cooler

Reply #19 – April 04, 2016, 11:43:10 am

Quote from: wolfe10 – April 04, 2016, 10:31:15 am

NO, yours is external. Follow the large diameter tubing from turbo to CAC and from CAC to intake manifold. It is in front of/outboard of the radiator.

Found it, thanks, Brett

Re: Check your air cooler

Reply #20 – April 05, 2016, 12:32:38 pm

Thanks for clearing that up Brett. This thread reminds me that I should put more efford into finding out for sure if this 3208 has an internal water to air intercooler or not. Pretty sure it doesn't, which means it would be a good idea to figure out a intercooler setup for a rear radiator u280....in all my spare time with no ither projects hangin over my head.

Re: Check your air cooler

Reply #21 – April 05, 2016, 01:12:26 pm

Quote from: twobus – April 05, 2016, 12:32:38 pm

I should put more efford into finding out for sure if this 3208 has an internal water to air intercooler or not. Pretty sure it doesn't, which means it would be a good idea to figure out a intercooler setup for a rear radiator

I would hope yours is built into the engine somewhere, my side-mount is really jammed in there, and would think a retro to your rear mount would be spendy, if even possible. (Those are some VERY serious connections, in and out). I know our radiator was made by Atlas in San Antonio, maybe they made the inter-cooler, as well. Post some pics if you dive in!

Re: Check your air cooler

Reply #22 – April 05, 2016, 02:43:06 pm

Quote from: twobus – April 05, 2016, 12:32:38 pm

Thanks for clearing that up Brett. This thread reminds me that I should put more efford into finding out for sure if this 3208 has an internal water to air intercooler or not. Pretty sure it doesn't, which means it would be a good idea to figure out a intercooler setup for a rear radiator u280....in all my spare time with no ither projects hangin over my head.

Did not need an intercooler on a 250hp 3208 cat.

For fun had a few customers bolt on a marine twin turbo top end on them. Radiator was big enough. Only ran them hard in high gear with the torque converter locked up as the 643 is not rated for that much torque.

100k miles later everything was fine.

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