Toyota Hybrids: inverter coolant change interval?

[newoilguy1]

Toyota Hybrids: why do so many recommend a longer inverter coolant interval than engine coolant?

Why do so many independent mechanics recommend a longer service interval for inverter coolant than for engine coolant?

Just curious.

 

[Owen Lucas]

Eh, I wouldn't get involved in flushing the coolant on these systems. Sounds complicated, maybe there is a specific procedure to burp it? I presume these inverters don't get hot enough to stress the coolant much anyway, so maybe this is why they can last so long?

 

[Stimp]

The inverter/dual motor-transmission coolant loop, at least on the 2nd gen Prius was super easy to drain and gravity fill. It's just a matter of differentiating between the transmission fluid drain plug and the coolant drain, because they look similar and are close together. It has a large aluminum heat sink with myriad small passages, probably equally or more important to keep fresh coolant there than in the engine to prevent corrosion.

 

[Drifter]

The Toyota maintenance schedule calls for replacing the engine coolant at 100,000 miles/120 months; and, replacing the inverter coolant at 150,000 miles/180 months. Check your manual to confirm.

 

[eljefino]

By what action do you think it goes bad?

 

[Marcozi]

By what action do you think it goes bad?

Internal corrosion due to bad/incorrect coolant. I'd change it when the engine coolant is changed.

 

[benjamming]

By what action do you think it goes bad?

depletion of corrosion inhibitors
But I agree with what I interpret to be your view in how you're couching the question. I doubt it needs to be changed very often. Manual may be a little optimistic so go OCD and change at half the interval?

 

[02zx9r rev2]

When my daughter in law bought a 2009 Camry Hybrid with 245K miles on it, I did a radiator drain and fill and inverter drain and fill. I used Toyota 50/50 and the drained fluid looked just like the new fluid.

I was just doing preventative maintenance on it. Had no plans on doing it again after the first time. Didn’t have to worry about it the car was totaled soon after

 

[PandaBear]

Toyota Hybrids: why do so many recommend a longer inverter coolant interval than engine coolant?

Why do so many independent mechanics recommend a longer service interval for inverter coolant than for engine coolant?

Just curious.

My understanding is a small amount of combustion byproduct get pass head gasket and get into coolant, so no combustion product, less coolant wear. Another one is the electronics don't get as hot as the gas engine so it last longer.