Observations From 100K Coolant Change

[Mike Murrell]

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 baby 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 from above 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..

[2XOverhead]

Good info. Reminds me that I gotta change mine soon.

[kathyricks]

Originally Posted by Mike Murrell

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.

The radiator of my Corolla that was built in Dec. 1988 looks brand new too after nearly 20 years (see photo below) I never even drained the engine block or flushed the system - I just drained and refilled the radiator every two years with a mixture of 50% Toyota Long Life (red) coolant and distilled water. No flushing is needed because if the owner always uses the Toyota brand coolant there is no significant corrosion or mineral deposits to flush out.

The Toyota Super Long Life Coolant (pink) should be used in the 2004 and newer models because it was the factory fill. The Toyota red coolant was the factory fill in the 1987 -2003 models.