FYI Rear Radiator owners

[Bob Nodine]

We developed an oil leak a few years back and after repairing it I cleaned the radiator and CAC. We went to Alaska and got on some very nasty roads dust wise. On the way back we started developing overheating trouble and I wash the radiator in a campground in Calgary. On the way to Montana we still had overheating issues although there was some improvement. At a campground in Helena I used a garden sprayer and hose wan sticking them thru the fan blades to wash the radiator and CAC. There was an improvement but the coach still did not cool like it did before the oil leak. Next I replaced all the hoses, thermostat, and the coolant and cleaned the radiator again. Additional improvement but still did not cool as it should and would overheat on grades. I saw the recent post where a guy recommended using a commercial foaming coil cleaner and thought I would give that a try. I purchased it but still have not used it. Plan to tomorrow after I pull the coach out of the garage. I just could not convince myself that it would take care of the problem and decided to first pull the CAC so I could see the other side of the radiator and do a better job of cleaning it. That happens tomorrow. Thought some of you might be interested in what the other side looks like. There is just no way to get a radiator clean with the usual cleaning methods after you have had an oil leak. I was surprised to find that the CAC was in worse shape than the radiator.

[Harvey Babb]

I had a problem with oil mist from the road draft tube sticking dust to the radiator. I had pretty good results using an engine cleaner concentrate called Gunk SC mixed with Diesel and sprayed on from the fan side, followed by washing with a water hose and sweeper nozzle.

The Gunk/Diesel loosens the oily dust and carries detergent with it so the water will flush it all away.

If you use this be sure to follow directions on the container and thoroughly rinse all the cleaner off as it will attack the paint on the radiator if left on too long.

 

[DavidL]

Power washer to the rescue.

[Dennis H]

50 minutes ago, DavidL said:

Power washer to the rescue.

One MUST use extreme CAUTION if using a power washer. It's NOT RECOMMENDED for a reason. Those tiny fragile fins? They're there for a reason. Better to use a garden sprayer with cleaner, such as Simple Green Pro HD. Even then THAT must be diluted 3-1 before use. Gently spray it on, then hose it off. If the run off is dirty, repeat until the run off runs clear. Damage those fins and you'll be forking out big bucks to correct it.....Dennis

 

[DavidL]

Not recommended by who?  Someone who has never used one?

And those fins are not so delicate re: power washer.  I just did my wife's Escalade radiator / trans cooler that blew a power steering hose.

And BTW, even when those fins get ripped out, the core generally stays fine.

Do you do much DIY repair / fabrication work?

 

A technique:  You don't spray radiator fins from the side.  Straight on.  That blows the crud right out the other side and the fins don't get much pressure because the water just blows by them.  Something Simple Green would have a hard time doing.  Nothing wrong with SG for degreasing.  But it doesn't get crud off very well.  The dirt and junk trapped in the corner of the OP's radiator wouldn't budge with a gallon of SG soaked on it.  You need the mechanical action of higher pressured water or, like the OP demonstrates, a delicate touch of a screwdriver, wire brush, etc.  BTW, a wire brush has lots more chance to damage fins if you stroke against them and not with them.  Each tool requires knowledge of how to use it properly.

Edited September 4, 2020 by DavidL

[Bob Nodine]

It is still dark here at the house so I have not started on cleaning the CAC and radiator yet. So thought I would add a little more information just in case others plan to pull their CAC. First it is one hell of a job for a 74 year old and not for the faint of heart. As with many things Monaco screwed up on the opening size on the rear cap and the CAC cannot be pulled straight back to get it out of the coach. I had to learn this the hard way as I do most things. I made the mistake of starting inside the coach and removing the closet doors and both engine floor covers. I managed to get the clamps removed (thanks Van for the tool recommendation) from the CAC tubes on both sides of the unit leaving the 8 inch rubber flex joints and clamps at the CAC input and output tubes in place. Then I went to the rear where I had already removed all the bolts and C-channels. Tugged on the CAC and managed to get the hoses to pull off of the steel pipes. That was when I realized my mistake because there was no way the CAC was coming out with the 8 inch rubber hoses and clamps still attached. That is when I ended up removing the two hoses from the outside, both side panels, and all the mounting brackets so the CAC could be twisted in the opening and worked out at an angle. Obviously when Monaco dropped the house on the chassis they did not give any consideration to future maintenance of the cooling system. If I ever have to do this again I will know that it is not even necessary to go inside the coach and all the work can be done from the rear.

[Pampero]

I worked as an auto technician for 40 years and that is a common problem. Oil sticks to the radiator and holds the dirt.

Usually in RV the set up is the same as in cars, The AC evaporator is on front of the radiator.

I still use this product. Sprayed it throughout the ac condenser and radiator, let it socked an use a water hose. I would not recommend a pressure washer, 2000 lb plus can damage the aluminum radiators.

Do it couple of times, even your dash AC performance will improve

[quick_tox]

Dirtiest radiator/cac I've ever seen!  Here in Kalifornia we must build a lined containment trough to collect the contaminated cleaning solution and take it to a hazardous waste disposal facility. They only accept 5 gallons at a time so I have to drive around 3 times.

[Bob Nodine]

18 hours ago, quick_tox said:

Dirtiest radiator/cac I've ever seen!  Here in Kalifornia we must build a lined containment trough to collect the contaminated cleaning solution and take it to a hazardous waste disposal facility. They only accept 5 gallons at a time so I have to drive around 3 times.

Robert that sounds like a difficult place to own a motorhome. I spent most of the day yesterday cleaning up the engine, rear engine area, CAC, radiator, all the panels, and the fan. If you look in one of the photos I previously posted you will notice that the fan is black. Well, its not black and it took a lot of scrubbing but now is a cream color. I had to use a putty knife on the front of the engine behind the fan to get the caked up oil an dirt off. I have two long concrete driveways, one in front of the RV garage and the old one where the coach parked before the garage was built. I had the coach pulled out in one driveway and the other driveway littered with parts.  There is a slop from the driveways down to the street and all the water ran to the street. My water bill will definitely be higher next month and if I lived in "Kalifornia" they would have me cuffed and in chains by now.

When I washed the radiator I sprayed it down a number of times with cleaner and after waiting for the chemical to work would spray water thru the radiator making sure it came thru the back side. The driveway underneath was filled with dirt. I repeated this until the water came thru the other side clean in all areas of the radiator. Once I thought the radiator was clean just for good measure I stuck the hose inside the fan housing and sprayed from the other side. Much to my surprise there were areas where the water came out gray even through it was white going from the other direction. I spent another 30 minuted going over the entire radiator from the fan side to make sure the water was clear over the entire radiator. It took a long time to wash all the back dirt off the driveway after pulling the coach back in the garage.

I had a scare when I went to pull the coach back in the garage because the engine would not start. After turning it over about three times I remembered I had stuffed rags into the CAC tubes to keep the water out. Went back to pull them out and the one on the intake side had been sucked into the engine. That tube is about two feet long and curves into the engine. The rag could not be seen and my heart almost stopped. I always carry a three foot long flexible grabber and stuck it down the tube around the curved section and after a few attempts managed to get the rag out. It is time now to start putting things back together but I think the wife has some things for me to do today so it make take a few days to get all put back.

[jim.hamblin]

What year and how many miles are on your coach Bob?

[CTerry]

Every couple of years I have sprayed my radiator and aftercooler with Simple Green, let it soak a while and then used a pressure washer to clean it out. You do have to be careful and spray the radiator straight on to keep from bending the fins. Lucky for me the AC is up front behind the front step. Some times I have to do it two or three times to get clear water. No problems so far.

[Bob Nodine]

1 hour ago, jim.hamblin said:

What year and how many miles are on your coach Bob?

2006 Diplomat with 118,000 miles of which I put 106,000 on myself. Purchased it when it was one year old with 12,000 miles on the odometer. The plugged radiator and CAC are the results of having an oil leak just behind the fan and making an 8,000 mile trip to Alaska and back. There are many miles of dirt and gravel roads in the Yukon and the dust is so bad you have to maintain a 1/4 mile between vehicles. There is lots of small gravel that made its way into our fan housing as I am now aware of because I pulled the CAC and took a good look after washing everything down. Standing at the rear and looking into the engine area you can see the rock guard at the bottom that I am sure was a big help keeping the gravel out of the fan. But if you look to the right (passenger side) there is a large open space that is strategically located to allow gravel thrown by the rear wheel to make its way up into the fan housing. Not that we are planning another trip to Alaska but if we did I would not take a rear radiator coach on the trip. We had one of those canvas rock blankets attached between the coach and the toad but I think it is only good to stop the big stuff. We had a lot of rock damage to the front of our Ford SportTrac and many small pebbles in the wiper area of the windshield. It is hard to comprehend how much crap gets tossed up from the roadbed when you are on a road that is being repaired in the Yukon. There were many miles of road under repair and definitely the worst part of the trip.

If I had known how bad the oil leak was I would have fixed it sooner. It was on the engine oil fill hose and I did not anticipate the quantity of oil that ended up leaking out. Below is a photo showing where the leak was and there is a link to a write up I did on irv2 about the repair.

https://www.irv2.com/forums/f115/heads-up-for-monaco-rear-radiator-isl-coach-owners-409665.html

 

[TomV48]

Bob.  Looks nice and clean now!😁

[Bob Nodine]

7 hours ago, TomV48 said:

Bob.  Looks nice and clean now!😁

Actually Tom that photo was taken before I washed the engine. If you look below the white arrow you can see caked dirt and oil and it is difficult to read the ISL. I failed to take a photo after washing the engine before I put the fan back. Here is one with the fan back on after I cleaned it up. If you look to the right of the fan you can see the concrete floor of my garage. That is where a lot of the gravel came from that got into the fan housing. Now that I know this I may install some mesh wire in that area. 

Edited September 7, 2020 by Bob Nodine

[quick_tox]

Deja Vu. Mar

[TomV48]

Yikes.  Now you have given me a complex.   I see that I have a lot of cleaning to do As soon as this heat breaks.   Thanks for re calibrating my standards of clean.

[Bob Nodine]

We just traveled over to Maggie Valley from home and I am happy to report that all the work has paid off big time. The highest temp I saw was 191 for a few seconds on a long hill. Most of the time the temp is not even high enough to open the thermostat at 185 and the transmission never went over 179. Another benefit was a significant increase in power which I attribute to cooler air at the engine intake. The CAC was about 50 % blocked from all the oil and dirt. We have suffered with this for years now and should have pulled the CAC long ago.