Radiator Goop Hidden Inside Shroud

[andyshane]

I thought you might benefit from this. It might save you a gob of money, in the long run.

After friends sent their Discovery in for radiator service and ended up with a huge bill, I starting getting more serious about tending to mine*. Bear in mind the buddy who owned mine prior to our purchase periodically raised the closet floor and shot degreaser onto the engine and radiator, and I've done the same every six months or so in nearly two years of steady use.

We had been overheating, but only under extreme conditions, eg making 2-mile constant climb at 60 mph in N. Arkansas with 100+F ambient temps (120+ against the pavement). Even then, a short downhill run with the exhaust brake on to boost rpms, or pulling over resulted in immediate return to normal.

A recent trip to Galveston resulted in perfect temps, albeit with 85F outside.

Still, after the trip, I applied degreaser to the aft side of the radiator, waiting 20 minutes, shot the fins with a safe blast from the hose.

What looked like mouse turds showed up in the driveway.

Lil' greasy mouse turds that turned into a smudge when rolled between my fingers, rather than the wholesome, nutty but slightly gritty goodness of the real thing... Clearly, the engine side of the radiator was a muffin mold of sorts for these little pellets.

Using the heavy duty degreaser in a spray bottle, I hit it from the back side -- the idea was it'd pass through to the engine side -- another five or so times, waiting and rinsing each time.

The next morning, I jammed a digital camera up inside the shroud and shot a series of photos. One spot on the lower right was gummed up solid, despite repeated cleaning.

So, I got a gallon sprayer and loaded a 1:4 mix of the Simple Green Pro HD from Home Depot yesterday, rated safe for aluminum, sprayed the engine side of the radiator while hot, let it sit for 20 minutes and then rinsed. There was quite a difference, althought further cleaning was needed.

As a result of this discovery, I'm programming a misting of degreaser up under the shroud on the engine side, after every trip. It only takes a minute or two, can be paired up with hooking up the black tank rinse, done at the same interval.

Thanks for the comments below. Indeed, the moral to the story was that degreaser must always be applied to both sides of the radiator, with an emphasis on the upwind eg front side. Use good judgement to protect the delicate fins: some pressure waters have "Delicate" tips and are appropriate; if in doubt, use a hose-end sprayer.

[wolfe10]

Andy,

Glad to hear you switched from an engine degreaser to one that is ALUMINUM SAFE, as most CAC's are made of aluminum.

And, as you discovered, it is the FRONT of the CAC where most of the debris is located. Cleaning from the back is OK, but you must clean from the front.

Brett

[wildebill308]

Do not use to high of pressure as you might bend the fins on the radiater or cac. I would rinse every time I sprayed with degreaser.

Bill

[john_harris]

I had been seeing similar issues and took my HR Endeavor into Cummins for possible t'stat replacement only to find the same type of build up on front side. They found radiator pretty well choked off. even found a wendy's cup and other paper debris. We have a Liberty toad but otherwise have not restrictions on air flow. Any suggestions other than making sure it is cleaned more frequently than every 5 years.

[wolfe10]

John,

Yes, a rear radiator/CAC needs to be cleaned at least once a year from the rear AND from the front, as the front is where the vast majority of the debris accumulates.

Also, be sure that your crankcase breather hose has been extended to behind the fan shroud or you will add oil vapor to the dirt to insure that you will need to pull the radiator and CAC to get it clean!

[jc21014]

When everyone refers to the front of the radiator, is that looking at it from the outside of the mh or from the inside? We have the side rad on our DSDP but I see a cleaning in the near future.

[wolfe10]

On a rear radiator, front is front of vehicle. And in most applications where you have a SANDWICHED cooling system, the CAC (Charge Air Cooler) is in FRONT of the radiator. Since the fan pushes air from the front and it exhausts out the back, most debris is "filtered" by the front of the CAC. That is why the majority of your cleaning must be done from the front-- accessing the area from the bedroom or closet.

On side radiators, air is pulled by the fans from the outside and exhausts to the engine room. Most debris will be on the outside of the CAC-- hence much easier to get to to clean.

[jc21014]

Thank u for that info Mr W. Our ISL 370 Cummins is the side rad so should be easier to clean.

[andyshane]

The new Beaver doesn't seem to have this problem, with its side-mounted radiator. Big difference.