Cleaning The Radiator & CAC

[wolfe10]

1700- 1900 is a good choice for your ISL, particularly if at less than WOT. Peak torque is at 1300 and peak HP is at 2100.

I would compare cost of replacing the single window shift pad with the two window shift pad with aftermarket monitor systems that will provide you with that and a LOT of other information.

[jleamont]

OK, are the connections the same? Is it just a plug and play so to speak?

Oh yea, I had plenty of throttle to go, I just didn't want to push it that hard.

[wolfe10]

Yes, most plug into the diagnostic plug. And most coaches have a diagnostic plug in the dash area.

I was not concerned with the "gear you are in", a week on the mountains pretty well got me used to knowing. You could also do a speed vs gear spread sheet and tell from speed and RPM what gear you are in.

I installed a ScanGauge D in our coach-- plug and play. Some very good choices for what you can monitor for under $170:

http://www.scangauge.com/products/scangauged/

Silverleaf offers more, but is also a lot more $$.

[jc21014]

Our mh is the ISL 370 with the side radiator. Does the fan pull in air through the outside grill then towards the engine or does it push air from the inside engine area outward through the radiator, etc.

[wolfe10]

Our mh is the ISL 370 with the side radiator. Does the fan pull in air through the outside grill then towards the engine or does it push air from the inside engine area outward through the radiator, etc.

Flow on a side radiator is ALWAYS outside to inside.

The fan sucks the air through:

Dash A/C condenser on some models

Charge Air Cooler

Radiator

On some hydraulic fluid cooler

On some fuel return line cooler

On some separate transmission cooler (most have it incorporated in the radiator)

[jc21014]

Thank you. Sometimes there are occasions when I look/read information and a glaze forms preventing any level of comprehension.

[jleamont]

Thanks Brett, I had no idea such a gadget was available. This will help with a few odd things that keep popping up while I am driving so I can verify that it is just a guage problem.

My trans temp only warms up to 150 degrees, sometimes it goes backwards and the volt meter dives to 12.8 from 14.0 only when the dash lights are set to bright, as I dim them down the volt gauge rises back up, no other lights have any effect on that gauge but the dash dimming.

I ordered one now I can monitor with a digital display and I will feel more at ease.

[wolfe10]

"the volt meter dives to 12.8 from 14.0 only when the dash lights are set to bright..."

Very likely just a bad/inadequate ground wire for dash lights. Tighten the existing ground wire or run an additional ground wire to chassis metal.

[Ianinnapa]

So...took out the floor next to the bed to get at the CAC on my 2005 Bounder. Couldn't see a darn thing but the top of the engine. Replaced it and took out the floor in the closet. I could see the top of the fan but aside from pulling the fan and the cover, had a really hard time getting water, let alone simple green, in there. Not sure if I got any on the CAC at all but tell you what, my hands were greasy...

Any suggestions on doing this better for the future?

Signed Big Hands McGee.

Ian

[wolfe10]

Ian,

As you found out, there is no guarantee that the coach maker even considered access to that area.

On many, it IS a dirty job.

[Ianinnapa]

Brett,

My only thing was that I wasn't even sure if I was spraying what I was suppose to be spraying...I am guessing some form of 'wand' attachment will be beneficial in the future.

[wolfe10]

Ian,

If you will be in Madison for the FMCA Convention, come to the Caterpillar Engine Seminar. I have some good slides of this and will go over the "how too's".

Friday, July 31 1:30 p.m. Caterpillar Seminar: Seminar 7

[Ianinnapa]

Brett,

Unfortunately I will not be there. Any chance you are able to digitize them and post or email?

Ian

[john kelley]

Following up on my previous posts, and looking @ many similar concerns, I will share my recent solution. 10 year old ALFA rear pusher, with cat C7, overheating on any grade. In recent years, I have had radiator steam cleaned from the rear, added engine breather extension, and always wash radiator from rear and CAC from front side with water and simple green before every trip, yet, can not get out of the flat lands without overheating.

Finally gave up and took it to my local Freightliner shop to pull the radiator/CAC as a very costly last resort. What I found was unbelievable..................my forward radiator surface was 75% occluded with dark crud, as was the opposing rear surface of the CAC similarly occluded.

In addition we found a large dinner plate sized compact wad of grass/leaves/straw near the bottom of the gap between the two! I don't know how I drove around the block without overheating. And these findings in spite of aggressive cleaning routine that seemed to be what all have recommended.

We changed the serpentine and water pump belts while in there, and replaced both thermostats. I am anticipating lots of future 'cool' miles now, but do not understand how such a quantity of organic debris got between the cooling units, and why my water/simple green cleaning routine made NO impact.

Frustrated with my Freightliner

John

[jleamont]

john kelley,

Sorry to hear about the cost but great you found the root cause. Sounds like you will be able to run down the road much cooler now.

[Mattera68]

WOW!

That is all I can say right now. I was sent a link to this topic about over heating and I read through all the comments. I then went out to my coach and crawled into the engine compartment to look into the fan to see how my radiator/CAC compared to some of the stories since this is the first I have heard of the issue. Did I mention WOW! What little bit I could see was absolutely filthy, I'm almost embarrassed to admit how bad it looks. I guess I'm heading out in the morning to get a couple of gallons of simple green and start cleaning.

I hope this takes career my issues.

Thanks for the link, Brett.

[jleamont]

Brett, once again you have saved my sanity. I installed the scan gauge just before we left for a small weekend excursion. None of my gauges are accurate! Oddly enough the transmission is probably the closest to being accurate

I pulled a 9% grade at 1900 rpms and while the dash gauge went up to 205 degrees the coolant temp was at 185 degrees on the scan gauge. To make things worse the campground exit was just at the bottom of the hill so I started the hill climb at 0 mph and accelerated my way up to 35mph. So the moral of the story is I never really had a hot running engine, just a bad gauge reading. I am glad I cleaned the radiator for a good PM measure and I will continue to do so annually.

Previous trips (last year) I had my OTC Genesis connected, which streams data at an extremely slow rate and there is so much to read while driving I would miss events, so it quickly became a headache and I had abandoned that process last year after one trip.

My coolant temp is 180 degrees; it only climbed up to 186 on the wicked hill and stayed at 180 the remainder of the trip.

My volt gauge is 1.6 volts lower than it actually is. I held a steady 13.9. I did notice later in the trip it dropped to 13.4 for maybe 1/2 hour then came back up. I am assuming it was charging the coach battery bank at that time since the refrigerator was running.

My oil pressure is reading 15 psi lower than actual.

My Trans temp is reading within 5 degrees lower than the actual temp; average temp was 155-162 degrees, while my gauge is somewhere in that range. Other than the occasional bouncing which appears to be a ground issue.

[Mattera68]

So I got out and did my1st cleaning of the radiator/CAC. I soaked it as much as I could with about a gallon of simple green, waited only 5-10 mins and started the rinse. I remembered that I just last year bought a wand to use in my hot water heater to help de scale inside. This wand has a 90degree bend at the end and the overall length is about 15-18". This worked perfect, with that angle I could shoot at just about any part of the radiator, I couldn't see it all but I'm pretty sure I got to most of it. This wand is thin enough that it fit between the fan blades and I the shroud, I just watched all the black gunk peel off with the water pressure, I plan to do another cleaning but we are heading out Thursday morning for a weekend trip so I think this treatment is good for now. Just wanted to share my wand idea, hopefully it helps someone get theirs a little cleaner. Thanks to all for the info!

[jleamont]

Mattera68, keep it up and you will succeed.

Thanks for the wand idea.

[john kelley]

Following up on my previous posts, I just picked up my unit from my local Freightlner shop after a radiator cleaning. They were extremely helpful. My cost was in excess of $2700 to have the radiator and CAC pulled out and cleaned. Both were heavily blocked on their inner, opposing, unable to see, surfaces. Unfortunately, this resulted after following much cleaning advice over the years, using the simple green and water method, lengthening the crankcase breather, etc. My technique may not have been aggressive enough. Incidentally, most warn against pressure washing the radiator/CAC, but I routinely used pressure, albeit from a distance of 3-4 feet away. In discussing this with the Freightliner technician, he said they routinely do use pressure washing on diesel radiators, full pressure, and from as close as 6-8" away, simply being judicious to keep the wand @ 90 degrees perpendicular t the fins. I am searching for alternative preventative cleaning steps, given my experiences.

Does anyone have experience with stronger degreasers, like Envirogreen extreme, or Purple Power, or Air Conditioner coil cleaners?? Many products state they are safe on metals, and biodegradable. I am aware that some products can be harmful to aluminum radiator fins.

Searching for safe solutions.................

John

[obedb]

Extreme Simple Green is supposed to be the gold standard. Designed for aircraft aluminum. Just short of $18 a gallon on Amazon. My Cat 330 rear radiator unit has never overheated even on long western grades, but mostly in the fall. Just over 21,000"miles on the odometer. Still have not done mine but it will happen in the next several days. Engine belts have recently been replaced/ all from below by a local shop. My plan is to get underneath with a large breaker bar and pull the belt off of the tensioner. Then I will be able to move the fan to more easily coat the CAC with a 50/50 solution of Extreme Simple Green. The hose off will also be much easier. I plan on using pressure washing on the outside of the radiator at a nearby car wash. Believe me/ it does not compare with the pressure washer that I have at home. Place has been there since the early seventies with no upgrades. Opinions are welcome .

[john kelley]

I changed both the belts, serpentine and water pump belt, along with both thermostats, and had the fan cleaned thoroughly; all this while we had the radiator out of the coach. In the ALFA with the Cat C7, there is NO room to touch the belts or tensioners from below. You can not even get a finger in the space; the Freightliner technician confirmed that.

My plan, as suggested by Freightliner, is to extend the crankcase breather extension even farther aft past the radiator than where I have placed it. I have used Simple Green, but have not tried Extreme Green, a good idea. In addition, I may do what another ALFA owner suggested, and spray the Simple Green thoroughly on the CAC, and the rear radiator surface, let this soak for a while before rinsing thoroughly. I had been applying the Simple Green by aspiration via the pressure washer, likely diluting the de-greaser too much.

On a humorous note, the professional technician suggested that to adequately coat the degreaser to the CAC surface, given the fan and shroud, and the impossible access beneath the aft berth, one must crawl out over the engine, and tease the spray wand/spray bottle fluid as best one can onto the CAC surface. He took one look at me and suggested I might get one of my small grandsons to perform this task!

Challenging dilemma, and always good to hear what others have experienced.

John

[wolfe10]

One more recommendation: Do not let the detergent/Simple Green Extreme on the CAC or radiator long enough that it dries on the surface. That will not help in dissolving or removing the grease.

[Ianinnapa]

Question. My Cat Bounder on the flats was registering 192 deg on the flats. Does that sound normal? I also believe my alarm goes off at 212. Doesn't seem like a great buffer.

Thoughts?

Ian

[wolfe10]

Ian,

192 is likely good for thermostatically controlled temperature. Newer engines are designed to run hotter. You can call the Caterpillar RV hotline with your engine serial number to verify the correct temperature: 877 777-3126.

Whether the alarm goes off or not, a 20 degree F rise over thermostatically controlled temperature does mean you need to go to "Plan B". Gear down, slow down, etc.