what's the inverter reservoir?

I don't know, but I have a strong suspicion it's for coolant for the electric motor and inverter.

The clues:

• , at various places (example, 105K mile checkup), they mention inspecting the engine and inverter coolant.
• On page 312 of the Owner's manual, under the Cooling System section, they mention two resevoirs for coolant -- one for the ICE, and one for the electric motor, inverter and converter.
  • 
    However, I emphasize that I don't know.
    
    If I'm right, the manual says that you should put "Toyota Super Long Life Coolant" in it. Not plain water.

 

This is the coolant for the inverter and high-volt electrical components. It is separate from the internal combustion engine coolant.

But I think we need someone else who has more technical experience to answer that question.

~Andrew

 

the Prius has a dual cooling system, one for the ICE and one for the Inverter/MGI/MG2. I just recentley found out that you need the scantool to prime the Inverter side, electric water pump that has to run to force the coolant thru the system. My understanding is the Toyota Super Long Life Coolant is the same as Toyota Long Life Coolant mixed with distilled water.

 

The computer interface that the Toyota techs have that plug into the car. It's only available to Toyota dealerships and authorized service centers.

Dave.

 

<div class='quotetop'>QUOTE(Frank Hudon\";p=\"12375)</div>

Are you refering to the electric pump that seats behind the driverside headlight, in front of the fuse box. Please mail me back. I just replaced one on a '05 I just finished rebuilding.
I have a great respect for your postings.

Regards

 

<div class='quotetop'>QUOTE(Frank Hudon\";p=\"12375)</div>

Different color, Different stuff.

 

<div class='quotetop'>QUOTE(DanMan32\";p=\"104616)</div>

Different color, Different stuff.
[/b][/quote]

How differnt, Can you elaborate

 

Does the inverter coolant go to the radiator as well, making the radiator a "two part" similar to the trans cooler in most cars with an auto? Or does it have it's own heat sink of some sort?

If heat for the cabin comes from the engine coolant(correct me if wrong), is it possible for heat to be transfered from the inverter coolant to engine cooalnt for purposes of heating the cabin? It seems possible if the radiator is like an auto trans, but more logical the systems seperate, with the engine liking a hotter temp (and coolant) than the electrical systems. That's the best reason I could come up with two different coolants... cool for an engine isn't cool for electronics. What is different about the actual coolant forumulas? Maybe different materials they flow through? Is the inverter coolant pressurized as high as the engine?

 

<div class='quotetop'>QUOTE(gschoen\";p=\"104646)</div>

I am also waiting for DanMan's elaboration on the difference in the coolant fluid. I believe the inverter coolant is pressurized by its own seperate electric pump (see Frank Hudson's) post above. This pump does not run off the engine as in conventional water pump. As a result has to be primed using the scantool.

 

You ask for it, you got it, Toyota:

Classic used red long life coolant (LLC) good for 30K or 2 months (some long life!).

HSD (I hate that designation, they are ALL Hybrid Synergy Drive) uses Super Long Life Coolant (SLLC) which is pink. It is good for the first 100K, 50K thereafter.

As you have been stating, there are two cooling circuits: one for the ICE, one for the inverter. The ICE circuit has a storage tank to keep coolant hot for a few days, which accelerates the time to warm up the ICE on cold starts.

On the classic, there was a separate radiator for the inverter, which is behind the AC condensor.
On the HSD, it is the lower section of the radiator assembly.
I don't think the inverter would put out enough heat to warm up the cabin. The heat from the inverter and motors is high enough to warrant using a cooling system, but still not that high.

 

<div class='quotetop'>QUOTE(DanMan32\";p=\"104688)</div>

Don't mean to beat a dead horse, i was a bit alarmed when you said different thing, different color. I dont suppose adding the red to the HSD won't kill the system. Correct me if i'm wrong.

 

I think the original question started out trying to know if the coolant that goes into the engine coolant reservoir is different from the one that goes into the inverter reservoir.

I don't know. Can someone who knows share their knowledge?

 

Both cooling systems use the same coolant type, the pink SLLC, as DanMan had mentioned above.

I believe that the inverter coolant loop runs well below 150 degrees f. when it is at full operating temperature, unlike an ICE which will usually run well above 200 degrees when at operating temp.

 

<div class='quotetop'>QUOTE(DanMan32\";p=\"104616)</div>

Different color, Different stuff.
[/b][/quote]
exactly the same color, I have 3 jugs of the old stuff and 2 of the new stuff under my work bench and the old stuff when mixed 50/50 with distilled water has the same color as the Super Long Life Coolant and the documentation from Toyota said it was the same stuff dilluted to 50/50 with distilled water and the price is virtually the same. Damn expensive water. With my refractor tester they both test the same.

 

the water pump for the ICE is the one behind the headlight. It pumps to the thermous in the wheel well in front of the LH tire. There have been reports here on PC of them having to be replaced. The rad has two sections one for the ICE one for the inverter and MG's. The water pump for the Inverter/MG's is under the inverter assy and is controled by the ECU for the inverter. It monitors the temp of the MG's and the inverter and cycles the pump on and off as required to keep the temps correct. On the Classic the system can be bleed with out the THHT but on the HSD system the THHT is required to bleed it.

 

I don't think I see a clear answer here yet. Well that's because the question was answered: the explanation of what the inverter reservoir is was answered. But another question sprung: is a different coolant used for both? Because the normal coolant I've used has a greenish color which later turns pink. I've never changed or refilled the inverter reservoir though so do both of these have to be changed or just refilled? I feel like the coolant in my prius never gets used.

 

toyota coolant starts pink and stays pink. a system in good working order will not lose any significant amount of coolant.