M923A2 Radiator Scale

fpchief

Active member
Steel Soldiers Supporter
965
135
43
Location
South Alabama
Started process of removing my thermostat and decided I would go ahead and remove radiator side tanks to fix a couple of small leaks. After the many many bolts I have them off and found some scale build up. I am no radiator expert....actually not an expert at anything in the civilian world. Is this normal for a radiator that may be original on an 88 M923a2? No cooling issues.
 

Attachments

Elijah95

Well-known member
Steel Soldiers Supporter
890
309
63
Location
Georgia
From what I understand, the military uses conventional green antifreeze; cheap, plentiful, simple. The problem with it in the diesel world is complex yet simple, see excerpt below. The military is aware of the problem and simply doesnt care to address it, just like they continuously blow up Detroit 2 stroke diesels running 15W40 when Detroit mandates straight weight oil because “We do not want to complicate our supply chain”

“Cavitation is the phenomenon in which vacuum bubbles are created in a liquid due to an external force. A common example of cavitation is the bubbles that emerge from the prop of a boat; they are in fact small pockets of vacuum, not air. These pockets are created when forces are rapidly applied to a liquid. In a diesel engine, cavitation is created when the cylinder walls rapidly expand and contract under the immense pressures created in the cylinder. At 2,000 rpm, each piston in an engine is moving nearly 34 cycles per second (the piston is moving down, then up 34 times per second), which translates into nearly 9 power strokes per second. In effect, this cyclic motion creates a vibration that causes a small vacuum pocket to form between the engine coolant and cylinder wall. The problem with cavitation is that the vacuum area must dissipate, and when it does so the engine coolant slaps against the outer cylinder wall. While the force against the wall is low, it occurs continuously and slowly erodes away the cylinder wall. Over time, the cylinder walls can wear to the point that a hole or crack will propagate. Coolant in the engine oil and/or engine oil in the coolant is often a sign of a hole in the cylinder wall for engines that are prone to fatigue failure due to cavitation.”

The conventional green coolant lacks proper SCA (Supplemental Coolant Additives) to protect cylinder liners, couple that with them quite often failing to service a truck later in life sitting at the back corner of base or local guard unit and you start accumulating corrosion related to the breakdown of coolant failing to protect parts.

So how do we fix this?

A full cooling system flush is in order, flush forward flush backwards with an actual coolant flush chemical if you wish, you can do it 100 times and you’ll never ever get everything out no matter how hard you try, I promise you that you’ll never ever ever get all the crud out, and your aftercooler is caked in the crap too. You truck desperately needs (2) things afterwards:


1) You can continue to use conventional green, or a diesel rated coolant; The latter of which I recommend more. If you decide to use conventional green, you must add SCAs, if you use diesel rated coolant with SCA additives already added that’ll work too.

2) add a coolant filter, it’s less than $100, will save water pump wear catching particles smaller than your eye can see, and replacement filters are less than $10 each at times, you can even purchase filters with SCA maintaining additive packages inside them.

If you’re installing the filter, simply T it in bypass style into both heater core lines, that way when it clogs you won’t build excess pressure or loose heat capacity of said heater core, also add cutoff valves on both sides of the filter so you can easily shutoff and replace filter without having to drain 5 gallons plus of coolant. Replacement is 2 minutes max.
 

Elijah95

Well-known member
Steel Soldiers Supporter
890
309
63
Location
Georgia
This is after spending nearly 6 hours flushing my engine forward, backward, draining, removing hoses, blowing through etc. water ran out crystal clear everywhere afterwards, you can’t get it all out without a filter. IMG_0260.jpg
IMG_0261.jpg
IMG_0262.jpg
IMG_0263.jpg
IMG_0264.jpg
IMG_0265.jpg
IMG_0266.jpg


Sent from my iPhone using Tapatalk
 

Valor

Member
66
24
18
Location
Apple Valley, Ca.
Started process of removing my thermostat and decided I would go ahead and remove radiator side tanks to fix a couple of small leaks. After the many many bolts I have them off and found some scale build up. I am no radiator expert....actually not an expert at anything in the civilian world. Is this normal for a radiator that may be original on an 88 M923a2? No cooling issues.
Always use distilled water with antifreeze in the cooling system to prevent scale buildup. Spring water, regular water contains minerals.
 

silverstate55

Big Dummy
Steel Soldiers Supporter
1,836
121
63
Location
Cedar City, UT
As I understood it, on older diesels (939-series & older), it is best to use Low-Silicate formulated coolant, typically green, and add the NAPA filter with SCAs in it once the system is flushed. @Elijah95 showed that you might want to change your coolant filter shortly after a flush! Newer formulated coolant (red, orange, and so on...) might not be safe to run in older diesels due to the new coolant weakening seals/gaskets, as was explained to me by several competent diesel techs. So I tend to stick to the older formulations. I’ve found a good type of Low-Silicate green coolant at Cal-Ranch & Tractor Supply stores.
 

fpchief

Active member
Steel Soldiers Supporter
965
135
43
Location
South Alabama
Yep,

We 100% used non SCA added green coolant (in military) I did do a good flush...used cascade...the whole bit. Used napa low silicate green and added SCA with distilled water.

But obviously I need to do it again with something that will remove the scale. The system was decently clean when I did the initial flush. By the records it showed coolant service in 2010 but most likely not a real flush.
 

Elijah95

Well-known member
Steel Soldiers Supporter
890
309
63
Location
Georgia
I don’t recommend it because I can’t speak for long term results, but I used ice machine cleaner because it’s cheap and readily accessible for me, it dissolved all the scale pretty quickly but you need a good bit of it.


Sent from my iPhone using Tapatalk
 

Elijah95

Well-known member
Steel Soldiers Supporter
890
309
63
Location
Georgia
Stuff will eat any scale and corrosion it finds but I’m not sure what it’ll do to seals and other things long term


Sent from my iPhone using Tapatalk
 

frank8003

Well-known member
Steel Soldiers Supporter
4,853
1,294
113
Location
Ft. Lauderdale, Florida
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website like our supporting vendors. Their ads help keep Steel Soldiers going. Please consider disabling your ad blockers for the site. Thanks!

I've Disabled AdBlock
No Thanks