Charge air coolers

[uffdaracer]

After noticing a loss of power on a recent trip in my 40ft. 2002 Monaco Windsor, I pulled into a Cummins Northwest facility for an engine check. The mechanic performed a pressure test on the Charge air Cooler (aka aftercooler), and found it to be leaking quite severely. After removal, (along with the radiator), they sent it to a radiator shop for evaluation. The repair facility, which has an excellent reputation, determined that it could be repaired, but, it seems like Roadmaster who builds the chassis and installs the power train, in their infinite wisdom, went cheap on the C.A.C. (as in offshore). Need I say more!!! Anyway, the construction uses thin tubes which are bent in a tight radius and I had several leaks at those points. Welding them and hoping no more show up would be a crap shoot. A new O.E.M. wouldn't be much better I wouldn't imagine so I opted for a new one built in the good old U.S.A. This one uses, If I understood correctly, forged tubes which the shop owner told me would last the life of the coach. Mine has 75K miles on it and the shop owner (who now has 4 in progress) told me I'm lucky, he has repaired or replaced them with as few as 8k miles! If you have a radiator issue, check the C.A.C. at the same time. It's about a grand for R&R and they come out as a unit, so you may save money down the road. By the way, if you have a side radiator, pull the side cover off and do a visual along the bottom of the radiator for rocks wedged between the shroud and the radiator. I found out the hard way with a pinhole from a tiny pebble that was wedged in there. That was about 2 years ago. I fixed the problem by bending the shroud down slightly as not to touch the radiator then filled in the 1/2 inch or so gap with RTV. This eliminated the wedge possibility by creating a level area along the bottom. If a pebble gets in there again, it should vibrate along to the back where it can fall out. I check it about twice a year and haven't had any more stone issues. The side grille comes out easily,6 screws.

[walt2137]

I posting this so that it may help someone that has a leaking CAC and also I was able to find the leak in my CAC with the engine at idle with a soap mixture sprayed on the CAC. My raidiator was a J&B specialities out of CAL that has had a lot of failures.

CAC Removal in 2000 Dynasty
Replaced 7-19-2009

On the 2000 Dyn with a ISC 350 Engine, to change the CAC you do not have to drop the radiator the CAC flange sits on top of the radiator and holds the CAC in position. I did not have to jack the coach up only used air leveling to air up the rear all the way and drop the front of the coach all the way (air leveling) unbolted the grill and AC condenser let the condenser hang to the side and then pulled the rubber shroud and sheet metal trim off, remove the bottom bolts holding the hyd cooler to the bottom of the radiator, backed off the two top bolts (1 1/16 nuts with a rubber grommet top and bottom, this is the bracket bolts that hold the radiator and all the other coolers to the coach) pull the coolant lines off and lay to the side then pulled the radiator back using a nylon jack strap to be able to remove the CAC bolts that attach the CAC to the top of radiator flange then removed the CAC out the bottom , took total of about 3 hrs to remove including figuring out how to do the job without removing the Radiator and 1 ½ hr to install not including the rubber skirt. Total cost $950 for a new core installed using our CAC caps 7/15/09 to Fleet air in Martsell AL Fleet Air Technology - Charge Air Coolers
You may have to unhook the Hyd cooler if the hoses are not long enough to pull out of the way, just remember when you do unhook there will be 5 gal + oil that needs to be caught.
Also plan ahead and get all new coolant hoses also a good time to do a coolant change.

[sc3283]

Uff, did you see a drop in your boost gauge upon noticing your lack of power?

[walt2137]

Originally Posted by sc3283

Uff, did you see a drop in your boost gauge upon noticing your lack of power?

Not UFF but If you have a ISC 300 or 350 you should have at least 24# boost, on my ISC I did notice a drop in boost and not that noticeable on power, my boost was about 21# max and I found the core leaking with soap where the tubes attach to the flange that attach to the end caps

[uffdaracer]

Originally Posted by sc3283

Uff, did you see a drop in your boost gauge upon noticing your lack of power?

Unfortunately, I can't remember the maximum boost pressure prior to the problem being noticeable. I did notice during the problem that maximum boost pressure under full throttle, was 20 PSI. I will compare that to same after repairs are done. Sad thing is that had I have known the problem still existed before we headed south for the winter, I would have done what you did. I have a large shop with a pit and am always fussing over the coach looking for potential problems. The shop said they had to remove the radiator to get to the CAC bolts. If you and I have the same chassis and configuration, then, obviously they are wrong. They estimate the repair along with the new CAC to be about $2,500. I will find out next Friday. Thanks for your post. This is a great resource! Mike

[walt2137]

Mike it would be about the same setup on the Windsor that the Dyn has on the CAC and Radiator, the price that they gave you is a super good price but I would think that they would have a new core installed using your old tanks. Good Luck hope they hold to that price and your Boost should be about 24 to 25# with the new CAC.

[uffdaracer]

After blogging all of my power loss issues, I solved the problem and would like to share what I learned. My 2002 Monaco Windsor ISC 350 had sudden power loss as I mentioned earlier. After taking it to a Cummins facility, They found serious leaking at the CAC. (I still had 20 PSI boost however) The facility replaced the faulty "offshore" manufactured CAC with a lifetime, quality, good ol made in the USA brand. The problem persisted!! I now had 25 PSI max boost but still no power. The "ace" mechanic at the facility grabbed his computer, plugged in, and road test. About 1/4 mile down the road he said turn around, go back, problem found. The "ambient air" sensor had failed. This did not show up on the screen or trip any codes in the coach. It took a road test computer to computer to find it. The failed sensor told the on board computer that I was at "high altitude", so fuel was cut down to compensate for the reduced available air, thus reduced performance or lack of power was the result. So, about 5 minutes labor and an $80 part later, I was down the road! This road test probably should have been performed first but the leaking CAC would only have gotten worse and would have been dealt with sooner rather than later anyway, but as it was on mine, the turbo was still putting out more than adequate volume to run the engine and overcome the air leak. I guess the message here is if it's a power loss issue, check the ambient air sensor first. It's a lot cheaper and in my case anyway, knowing the CAC was leaking, I probably would have waited until I got home and dealt with it with my labor in my shop and saved $KKK.

[HeapBigEngin]

uff....GREAT post with your results and feedback. I have an ISC in our F/Wood, and I will sure remember your advice re the ambient air sensor. Good stuff! Sorry you had the CAC problem...