Use the Spin-On filter setup, and if you want that "See it" type setup, add a large Sediment Bowl prior to or after the filter (i'd go prior to that way it collects larger stuff before it gets to the filter)

I beleive i've seen large inlet/outlet sediment bowls on sale somewhere before but i can't remember where.

Do cummins engines have the Threaded Plugs in the block like most other engines?  Pull 2 of em and flush the block that way maybe?

 

Unfortunately, the best thing to do is a total major flush until clear water comes out.  When I got a muddy engine, it usually took 2-3 hours, sometimes more to get all the crap out.  It is best to remove the radiator to get the best results, but it is not always critical. 

Step 1. 
Buy a bottle of radiator flush and get the coolant too.  Flush the engine, heater core, and radiator separately.  Flush the heater core by removing the heater hoses.  Flush it one way and then the other until the water is perfectly clear.  Cap or plug the heater hoses temporarily.  Remove the upper and lower radiator hoses.  Remove the t-stat and reinstall the t-stat housing.  Flush the radiator the best you can, and then the engine.  Reinstall the radiator hoses.

Step 2.
Fill the engine with water and start the truck with the radiator cap off.  Rev her up to get the water rushing around for a while.  You should see tons of water flow through the radiator.  Shut off the engine, pull the lower hose and let all the water goosh out.  Repeat until the water is clear.

Step 3.
Get the bottle of radiator flush.  Reconnect the heater core.  With the t-stat still out, fill the engine will water and radiator flush.  Start the engine and block the radiator fins with something so the engine will heat up to operating temp.  Rev it up a few times.  The radiator flush instructions should say how long you need to keep the flush chemical in the engine.  Now repeat step 2 to get the chemical out.

Step 4.
Reinstall your thermostat.  Add your coolant.  Add water until full.  Disconnect one of the heater hoses when filling the radiator to let out the air.  Reconnect it when fluid starts to come out.

It's a lot of work and time, and sometimes it has to be repeated again after a few weeks, but it is about the only thing you can do to clean that junk out.  Fresh coolant will prevent that stuff from forming.

 

might be time for a new radiator or at least pull it and take it to a shop for a flush and have it rodded out.

 

might be time for a new radiator or at least pull it and take it to a shop for a flush and have it rodded out.

My cores appear relatively clean. I think over the years, silica and scale has fell out and settled in the bottom of the block, lower than the lower rad hose block inlet. That way, it doesn't drain out when I pull the hose, but continually mixes once I add more coolant or water. Also both the inlet/outlet of the heater core are mounted above the core itself, so I'm sure it is holding sediments that don't gravity drain as well.

 

My cores appear relatively clean. I think over the years, silica and scale has fell out and settled in the bottom of the block, lower than the lower rad hose block inlet. That way, it doesn't drain out when I pull the hose, but continually mixes once I add more coolant or water. Also both the inlet/outlet of the heater core are mounted above the core itself, so I'm sure it is holding sediments that don't gravity drain as well.

another good reason to pull it and take it in, they can take the tanks off and clean it out

 

another good reason to pull it and take it in, they can take the tanks off and clean it out

I'm not pulling the heater core to have it boiled out lmao. That job is kind of a pita requiring 6 hours I don't care to spend.

As mentioned, the rad itself is clean. I pumped the crud out myself. I have cross flow rad so I can inspect it very easily.

The sediment has settled some place else (not radiator)

This is why I considered a filter, just let it catch what ever floats, over time. Then pull the filter in a month or 2 if I notice the outlet side is cold. Cut it open, inspect it, replace.

This probably has something to do with the fact I never paid attention to the fact cummins and diesels in general require a different kind of antifreeze than cars, and regular car green antifreeze is bad for them. (causes the sediment)

 

This probably has something to do with the fact I never paid attention to the fact cummins and diesels in general require a different kind of antifreeze than cars, and regular car green antifreeze is bad for them. (causes the sediment)

What's different about them? I would think the basic metallurgy is the same, albeit bigger.

 

What's different about them? I would think the basic metallurgy is the same, albeit bigger.

Well, I recall when I actually did work to diesels our antifreeze said "pre charged with SCAs" I never paid any attention to that.

Only later did I realize gasoline engines and diesels use much different kind of antifreeze.

Cummins do not require SCA precharge because they do not have cylinder cavitation issues like larger diesels.

They do specify a low silicate coolant though. ASTM D4985

I am not sure why higher silicate gasoline coolant is detrimental. I heard something about the vibrations and fall out is all I know.