Observations From 100K Coolant Change

[Mike Murrell]

The vehicle I'm reporting on is a 2004 Toyota Tacoma 2.4 liter truck, so some would say this doesn't belong here. That vehicle is a Toyota product and more importantly, uses the pink 100K SLLC(super long life coolant) that's used in all but one Gen 5 Tacoma and all Gen 6s, so my obervations from this coolant change are relevant in this forum.

Not being one that buys into 100K drain intervals for any lubricant/coolant, I decided this past weekend to change the pink Toyota SLLC(super long life coolant) in my 2004 Tacoma 2.4 liter automatic. The vehicles mfg. date is 12/03 and the odometer read 42,500. The coolant in the overflow bottle looked good and had none of the typical residual gunk you see in overflow bottles that use traditional coolant. About a week before, I removed the radiator cap and saw a orange-like hue in the coolant color. I wasn't sure if this was the beginning phase of corrosion build up and didn't want to take any chances, so I headed to a local Toyota dealer and bought 2 gals. of the pink SLLC.

I first removed and drained the overflow bottle into it's own container. The color was pink. No crud or dirt of any sort was in the overflow bottle. I normally have to scrub these out vigorously with a bottle brush. In this case, I simply rinsed it out a few times.

I next drained the engine block into another pan and removed radiator cap. This drained the block and about half or more of the radiator. Again, the color of the used coolant was pink. I noticed an orange-like hue in the color of this coolant in given light and when turning the pan gently from side to side. That's likely what I was seeing the week before, but had never seen that in the past as I check coolant color/condition from the radiator top as well as overflow bottle every month or so.

Last stop was the bottom of the radiator - loosened drain plug and drained the remaining 1/2 gal of coolant and again, the color was pink.

How did the color vary between the old and a sample of the new I poured into a clear plastic qt. container?

Not a huge difference, although the old had taken on a bit of a reddish color versus the new pink SLLC coolant. As I said above, the drained coolant looked pink upon draining, but the new coolant was slightly pinker.

The inside top of the radiator looked brand new. No corrosion or rust or any kind. No dirt or gunk of any kind was in either the pan that caught the block/radiator coolant or the pan that caught only the radiator coolant.

In my mind, this was the cleanest used coolant/cooling system I had ever seen after 4+ years of use.

Do I really believe the Toyota SLLC is really 100K coolant? I'll never know - didn't let it get that far and I have no regrets as the idea in maintenance is to change fluid BEFORE they wear out and not when they're worn out..

[TRD VVTi]

That's good to know.

[TRD_EarBanger]

Your coolant was clean to the naked eye and thats a good sign, but its a safe bet the coolant additives were in the process of wearing out or worn out...if you ask me, changing coolant every two years is easier than changing radiators and water pumps that wore out before their time -

[TRD VVTi]

I've always liked long life coolants. My '95 Formula has GM Dex Cool in it and there is no buildup or corrosion in the cooling system at all, even after 243,000 miles. Dex Cool powders up when it leaks exactly like Toyota Long Life and Super Long Life coolants also.

Seeing this repeatedly over the years has convinced me that the generic or cheap green antifreezes truly are inferior. The better and newer coolants are worth the slight extra cost.

[CharmCityES]

^^agreed.
its good to know SLLC holds up as well as it should...i have RED in my 03, since its an 11/02 build, but i will be swtiching over to PINK as soon as i change my coolant again at 60k.