Rear Radiator Cleaning Questions

SteveG · 09-18-2007, 01:17 PM

After reading a number of posts regarding the rear mounted radiator getting plugged with by-pass oil and road grime, I thought it might be prudent to do a radiator cleaning on our 2004 Journey 36G powered by a Cat C7. The readings made it seem like a pretty straight forward but messy job. I then crept under the motor home to plan the job... Holy mackerel! Where's the engine radiator?

All I saw was engine and cowling.

I wedged the drop light toward the fan cowling/radiator as far as I could get it and noticed that on the passenger side on the engine I could just see, through the fan blades, the engine radiator. On the driver side of the engine it was just barely visible. So I am thinking before I start this project I should ask, what is the best access and cleaning procedure? I guess I just saw it?

It has been suggested to purchase a sacrificial garden pump sprayer with a plastic wand so the wand can be flexed to reach further. Fill up the tank with something like Simple Green, pump up some spraying pressure and then work the wand up through those small passenger and driver side openings squeezing the wand between the frame, engine, wiring cables, hoses, fan shroud, fan blades and squirt the juice into the engine radiator the best I can. It doesn't look like to me that I will reach the entire engine radiator but maybe the spraying will cover more then I think?

Then do the same thing to the "charge air cooler" (CAC) from the back (standing at the back of the MH and looking into the engine compartment)

Do I dilute the Simple Green or use it straight from the bottle?

Then after waiting about twenty minutes, the wash down is done with a garden hose at low pressure spraying into what looks like the radiator but which is actually the "charge air cooler assembly (CAC)?" Water will penetrate the CAC enough to wash out the engine radiator that is mounted behind the CAC?

So am I on the right track?

SteveG · 09-18-2007, 01:17 PM

After reading a number of posts regarding the rear mounted radiator getting plugged with by-pass oil and road grime, I thought it might be prudent to do a radiator cleaning on our 2004 Journey 36G powered by a Cat C7. The readings made it seem like a pretty straight forward but messy job. I then crept under the motor home to plan the job... Holy mackerel! Where's the engine radiator?

All I saw was engine and cowling.

I wedged the drop light toward the fan cowling/radiator as far as I could get it and noticed that on the passenger side on the engine I could just see, through the fan blades, the engine radiator. On the driver side of the engine it was just barely visible. So I am thinking before I start this project I should ask, what is the best access and cleaning procedure? I guess I just saw it?

It has been suggested to purchase a sacrificial garden pump sprayer with a plastic wand so the wand can be flexed to reach further. Fill up the tank with something like Simple Green, pump up some spraying pressure and then work the wand up through those small passenger and driver side openings squeezing the wand between the frame, engine, wiring cables, hoses, fan shroud, fan blades and squirt the juice into the engine radiator the best I can. It doesn't look like to me that I will reach the entire engine radiator but maybe the spraying will cover more then I think?

Then do the same thing to the "charge air cooler" (CAC) from the back (standing at the back of the MH and looking into the engine compartment)

Do I dilute the Simple Green or use it straight from the bottle?

Then after waiting about twenty minutes, the wash down is done with a garden hose at low pressure spraying into what looks like the radiator but which is actually the "charge air cooler assembly (CAC)?" Water will penetrate the CAC enough to wash out the engine radiator that is mounted behind the CAC?

So am I on the right track?

skigramp · 09-18-2007, 03:49 PM

SteveG

What you have described is my second step ... my first step is to take my air hose and blow as much dust from the CAC as I can before I get it wet.

I have a large piece of plastic sheeting that I lay on my driveway to make the sliding underneath easier ... I fill my garden spayer with a diluted solution of Simple Green and spray every part of the radiator that I can see with the engine off ... then I start the engine and crawl back under again ... and making sure that I stay a long ways from the fan I spray more solution into the fan cage figuring that it will spread the Simple Green solution around ...

Shut off the engine and spray the CAC ...

let it set for 20 minutes ...

Spray with a garden hose ...

I also clean the air condition condenser coils on the side using Simple Green ... I spray those from the inside and outside ...

RKL2 · 09-18-2007, 04:28 PM

Confused a little..if you are standing at the rear of the motorhome, I thought you are looking at the radiator and not the CAC....I thought thr CAC was what you see from the engine side....Am I wrong? thanks RKL

Pusherman · 09-18-2007, 04:30 PM

You'll get lots of opinions on how to clean your rear radiator and charge air cooler. Many will agree on some aspects: DO NOT use a pressure washer to clean the radiator, as it may damage the fins.

I also use simple green. I spray it on, full strength, onto a hot radiator, from the rear side first, and then from the engine side (with all the challenges you have listed in your post).

Let it work for 10-15 minutes, enjoy an adult beverage, and then flush from the rear to the engine side. Repeat until what is washed off the radiator is clean.

I have a portion of my driveway (to my barn where the MH lives) which is gravel, so I do this cleaning here. Otherwise, you will make quite a mess on your driveway.

P.S. RKL -- you are correct.

fun time · 09-18-2007, 04:40 PM

One thing that I do is cover the engine with plastic, including the alternator, starter, compressor and electrical connections. While I realize they are suppose to be water proof, I personally do not want Simple Green getting into those components when spraying water from the outside in. Just my two cents worth. Have fun, it is a dirty job.

smlranger · 09-18-2007, 04:41 PM

The first time I did mine (bought my rig used so not sure it was ever done by previous owner), I also used full strength Simple Green in garden sprayer. I soaked the CAC from outside in but I also removed both engine covers under the bed and there is much improved access to the fan side (radiator). I was able to spray well inside the fan shroud. Since the motor was also grimey, I used some spray Gunk on the motor. Without the DW knowing, I pulled the garden hose through the bedroom window and sprayed everything well. I used covers on the carpet and, actually, did not have any mess inside the rig. I finished by spraying from the outside in.

SteveG · 09-18-2007, 05:02 PM

Thanks for the replies.

The CAC is mounted on the engine side of the radiator? I initially went to FreightLiner Access and it shows the CAC but at a second look it really does not provide orientation. Tomorrow I'll check the hose lines and that should show me what is connected to what. Not in the end that it will make any difference which is which as all needs to be cleaned but at least then it will sound like I have a clue.

I took off both engine covers and concluded it would not provide significant access. But I think I'll take another look.

Pusherman · 09-18-2007, 06:28 PM

Steve, yes, the CAC is on the engine side of the radiator.

smlranger · 09-19-2007, 08:34 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I took off both engine covers and concluded it would not provide significant access. But I think I'll take another look. </div></BLOCKQUOTE>

On a rear rad coach, there is no good access from the engine side. I just thought there was better access to the area inside the fan shroud from above the engine. You can at least shine a light into the rad and see how much gunk you have to deal with.

THutch · 09-19-2007, 02:41 PM

How often are you guys doing this? I just passed 23,000 miles on my 2005 and haven't thought about this. Am I due? I did hang a jug under the slober tube to catch the excess. I've emptied it once with about a half a quart in it. Probably need to look at it again, since Ive had the 22K service...

SteveG · 09-19-2007, 03:35 PM

I purchased the materials to do the radiator cleaning today. So looks like I ˜am running out of excuses. The little that I can see of it, the CAC looks filthy with dirt and not oil deposits. So that's a good thing.

I stuck my head under the radiator and confirmed for myself that the CAC is on the engine side of the radiator. It is always helpful to have the forum's assistance. Thanks.

Pusherman · 09-19-2007, 06:08 PM

Relative to the frequency of cleaning the radiator, the answer is --depends.....

On older coaches the slobber tube (crankcase ventilation) does not extend below the radiator, and this gunks up the CAC and radiator rapidly. These coaches need their radiator and CAC cleaned annually.

My new coach has the slobber tube extended below the radiator. I am guessing (as I have not done it yet on the new coach) that I can get away with cleaning it every 2-3 years.

kenbt · 09-21-2007, 04:44 AM

This summer I noticed that my engine tempetures were running a little higher than normal and decided to clean the radiator. As most of you, when I climbed underneath the coach, the radiator was completely unaccessible because of the fan shroud. So I went to the quarter car wash and sprayed the radiator from the rear with the engine off using there engine clean solution and then I rinsed it. There was no damage to the fins with the pressure from the car wash and it apparently did a good job.

KennethM · 10-05-2007, 02:44 AM

Thanks to all that posted their trials on cleaning the CAC was a great help to me not having to discover a method of access. I found some access on the passenger side from under the coach and also had to remove both engine covers under the bed for the best access to the CAC. I was really surprised how clean it was only a little dust but no grease build up at all and the slobber tube extension is the real key. The rear most engine access panel is the one giving the best access to the CAC but I also found a potential problem posted on the chassis forum. The suction AC hose was laying against the turbo charger output so I spilt a larger piece of heater hose and tie wrapped it in place giving the AC hose a buffer from the hot output of the turbo charger. The AC suction line can not be easily rerouted even with a system evacuation without some extra length and an angle fitting on the compressor. High pressure line takes a different path it is not in danger at all. Heads up again on this possible problem and this can be easily accessed and seen from the large forward engine cover under the bed on the 36G. Also found the gasket on the rear most engine cover was not pushed in place just hanging down on the drivers side back most corner and both cover gaskets had other places not fully snapped into the metal flange. Good thing they do not have to be water tight or I would have sank on the first trip. AC suction line did have a rubbed/flatten area on the hose with less than 9k on the coach.

Gary CA · 10-13-2007, 07:59 AM

Additional, cleaning radiator project. I completed this task yesterday with all the advice from forum members and thankyou.

My engine access assembly shell is screwed to the rear wall of the coach. Where the sheet metal screws to the wall, under the headboard, all 12 screws needed to be replaced. Six were missing and laying on the sheet metal and the others were loose. Also, on the passenger-side of the bed a section of foam was out of place and exhaust debris had marked the wall between the bed and nightstand. This foam seals the sheet metal vertical section under the matterss. Check these problem places when you do your project.

Like the man said, this is a dirty project but well worth the effort.