Coolant question

[northwest]

Searched the forums, and maybe there is an answer somewhere, but I can't find it. I did find something from January 07 that was close, but then it veered a bit off-track and I still am confused.

HEAVY snow stranded me indoors today...well, sorta...I took the opportunity to fuss around with the new Prius (08, ~400 miles). So, I opened things, poked things, generally monkeyed around with lots of stuff I probably shouldn't have.

Noticed the two coolant tanks. One that is basically hidden by a plastic plate and tucked up next to the radiator and the second out in plain sight next to the Hybrid drive thingamajig.

The one in plain sight is at the "low level," not below it, but "at it."

So, having a fine jug of that very expensive Toyota Red coolant handy, I was thinking of dumping some in. But reading all these threads, I have the old school "undiluted Toyota Red coolant" that you need to mix 50/50 with distilled water.

In these threads I am reading about some SLLC pink stuff. Is it ok to mix my Toy red coolant and dump it into that tank next to the fancy hybrid whatever it is. Or do I have to go to TOY and get yet another overpriced coolant....

[tochatihu]

Originally Posted by northwest

...

Noticed the two coolant tanks. One that is basically hidden by a plastic plate and tucked up next to the radiator and the second out in plain sight next to the Hybrid drive thingamajig.

The one in plain sight is at the "low level," not below it, but "at it."

So, having a fine jug of that very expensive Toyota Red coolant handy, I was thinking of dumping some in. But reading all these threads, I have the old school "undiluted Toyota Red coolant" that you need to mix 50/50 with distilled water...

"tucked up next to the radiator" is the engine coolant overflow reservoir. "next to the Hybrid drive" is the electricals coolant loop top tank. The level of the latter can only be checked when Prius is in "ready" and thus the electric coolant pump is running. Its level should then be distinctly different in the front and back of the tank. An experienced Prius driver with your model can confirm if it should be lower or higher; but different.

So you are not yet at the stage that you know the coolant amount should be changed.

For your car you should use SLLC which is pink and sold pre-diluted. I think it's about $20/gallon and you'll have to decide for yourself if that's excessive. The older, red LLC (which I suppose you have) is almost certainly compatible. If it is still undiluted, it would be appropriate to mix with an equal amount of distilled or deionized water. By the same token, it would not be a disaster if you needed to top of either coolant system with distilled or deionized water.

Your choices are to by the SLLC (if needed), or to top off as above, taking the responsibility upon yourself. I reckon that this is but a tiny risk, but it's all yours.

[Bear68]

Best advice I could give here is to simply add clean water. Even though the pink SLLC is premixed, some of the water content can and will evaporate over time. The very small amount of water needed to bring it up to the full line will not hurt anything and will keep the coolant pure. Mixing other types of coolant will shorten the life span of the SLLC which is 100,000 miles.
(I would highly recommend having it professionally serviced when it is time. Air bubbles in the system can destroy the invertor and/or the drive unit... Very Big $$$$!)