Casting Sand: 6.4 Hemi HD Coolant Filter

[Matt Luken]

Inline Heater Core Coolant Filter & Inspection System 5/8" VE-Labs CIFS-1 CFIS-1 | eBay

Inline Heater Hose Coolant Filter. : (The most popular size is the 5/8?). The coolant filter needs to be installed into the inlet hose of your heater core and is easy to install. It also regulates the pressure entering the heater core.

ebay.us

 

[Sherman Bird]

I just picked up a few bottles of CLR earlier today to use during my heater core flush this weekend. Bottles says it's Water, Lactic Acid, Gluconic Acid, Lauramine Oxide, Tripropylene Glycol n-Butyl Ether, plus blue and yellow dye.

I know how well the CLR has worked for me. I recommend it, but also caution to flush thoroughly with distilled water afterwards, to insure all traces of the CLR have been cleaned away before adding new coolant!

 

[Ramez]

Why not use the air water flush gun and push that crud out of the block??? My '16 Cummins was quite a mess too, now the heater rocks and coolant appears clean. If you won't touch the block you will get to do this repeatedly.

 

[Sherman Bird]

Why not use the air water flush gun and push that crud out of the block??? My '16 Cummins was quite a mess too, now the heater rocks and coolant appears clean. If you won't touch the block you will get to do this repeatedly.

That IS correct!

 

[mtofell]

I get the concept of getting all the crud out of the engine, putting in a filter, etc. but it's worth mentioning the vast majority of people are good to go after a heater core flush. I think cases of cores clogging over and over again in a short period are the exception.

At least that's my experience and what I've read for the majority of cases here. I'm at 11+ years, 145K miles and on my second engine (so, two loads of crap) and my core only clogged after my radiator leaked and the core ran dry. I flushed for +/- 20 minutes with an air/water gun and am all good. Even if I have to do it every year or two (which I doubt I will) I'll just do that rather than spend a bunch of time/money on things that might not need to be done.

 

[R.D.J.]

Ive owned my truck since new. First time I had to flush was November 2024. Then over the summer I flushed the cooling system out, air/water flushed the engine/rad and the heater core separately. Then in November 2025 I noticed poor heat again. I again flushed the heater core out and loads of debris/sand came out. Perfect heat now restored.

If I have to do that every year, so be it. My truck doesn't have the miles or use on it yet to justify removing the dash just for heater core replacement. Either it will be someone else's problem, or by that time, the EVAP will be restricted, HVAC box interior dirty, etc. Will be worth pulling the dash then.