Coolant Check

Remember somewhere I said that if we feed our diesel clean fuel, clean air, keep the oil fresh and don’t overheat it it will run a loooong time? This is part of the not overheating: ….Item # 20-03 on your maintenance checklist….

It says to replace the coolant every 100,000 miles IF the heavy duty SCA (Supplemental Coolant Additive) is in there….. which, according to Mike Cody at Camp Freightliner, it is.

It also says to test the SCA levels every 25,000 miles. So, also per Mike, I ordered the Fleetguard 3 way heavy duty coolant test kit:

Test Kit 1.jpg

Tesst Kit 2.jpg

So, we’re checking the freeze point, the Molybdate level, and the Nitrite level…. What do these do? They fight rust, scale and corrosion — and in diesel engines protect wet cylinder sleeves from cavitation. Google that, you’ll be reading for a while.

The instructions say to collect a sample. NOT from the expansion tank….but from the radiator or petcock. Oh dear, here we go again. Back to the world of “I can barely see it, let alone get to it….” So under there we go….. Well….. pleasant surprise. Passenger side bottom corner of the radiator there’s the petcock…..

Radiator Petcock.jpg

Squirt it with a little happy juice, let it sit for a minute and (regular lefty loosey) drain a little to flush out any crud, throw it out and then get sample….. Easy peasy.

Coolant Test 1.jpg

And do the test, per the instructions…..

Coolant Test 2.jpg

Tip nice and dark….. -30ºF protection. That’s enough. If it gets colder than that I got bigger problems. Middle pad… Molybdenum: Hmmm, that’s a little light. Gonna call that “Row 2 or 3″…… Nitrite: Nice and dark purple. Call it H. So, that puts me in the 3.5 to 3.8 SCA units per gallon. Carry on!

All that said, these test strips are not the MOST accurate thing out there. And since this actually matters a lot for the longevity for our engines I am considering sending it in for testing. Found this place… Will call and see what that that sets me back. Maybe around 50K miles or so, may throw in an oil analysis while I’m at it. Right before the warrantee runs out maybe? Meanwhile I’ll do another test in 10K or so…. see how it trends.

And of course we check the level. There’s a “cold min” and “cold max” on the expansion reservoir. It was a little low so I decided to add some….

What to add? The world of coolants is, to say the least, confusing. Specs, colors, additives you can read for days. After a LOT of searching I ended up on the Cummins Quickserve site and figured out that their highest spec coolant is CES 14603 And we’re looking for an SCA pre-charged. Prestone Command HD seemed to meet these requirements and I added about 2 quarts.

When I get my head further around the formulations and requirements I will try to provide more info here…..