Coolant Question Help

The coolant should be changed out at 100k miles. if you are close and haven't changed it out,this would be a good opportunity.

If you haven't driven the car since the oil change, i would just drain the overflow reservoir and add some zerex asian or toyota pink super long life coolant

 

I really doubt a pint of green coolant is gonna hurt anything. just get a gallon of the right stuff and keep it handy for next time.

 

Definitely siphon out the reservoir, and then fill with Zerex Asian
Mixing incompatible coolant formulations runs the risk of precipitates forming

 

Incompatible coolant will be a bad thing.

Zerek Asian formulation contains <10PPM of silicate and borate. LINK
Zerek GREEN contains upto 250PPM of silicate. LINK​

Best to go OEM. Toyota LLC (red color) and SLLC (pink color) are silicate, amine, and borate free.

• Only use “Toyota Super Long Life Coolant” or similar high quality ethylene glycol based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life hybrid organic acid technology. (Coolant with long-life hybrid organic acid technology is a combination of low phosphates and organic acids.) LINK, page 407
• Toyota LLC MSDS
• Toyota SLLC MSDS

Always read the bottle label to be assured of compatibility.

Zerek Asian says compatible w/ Toyota. But will <10PPM of silicate and borate (which Toyota LLC and SLLC lacks) be detrimental?
Zerek Green contains quite a lot of silicate, 250PPM. Will this be detrimental?​

Hopefully you followed JC's advice and siphoned out the incorrect coolant from the overflow tank. I personally would do this, but I would add distilled water instead of the Zerek Asian. Reason being, to avoid the silicate and borate, which Toyota lacks. If any distilled water was sucked into the radiator, the existing SLLC would just become a little diluted. Once home w/ the SLLC, siphon out distilled water from overflow tank, add correct SLLC. And, you may be at a mileage/time point, where it makes more sense to do a drain/fill of the old coolant?

Since we are talking coolant, Artsautomotive makes a compelling reason to change the coolant earlier. Granted he makes money when you agree to this service. However he is a respected repair facility, with a good reputation. LINK

The inverter coolant looks pretty good at 30K miles. The ratio and pH both test OK as well. So why are we changing it? Because:
1) Toyota SLLC is just regular ethylene glycol silicate-free premixed coolant with pink dye, and ethylene glycol coolant has had a 2-3 year service interval for as long as I can remember.
2) The components it protects (the HV transaxle & inverter) will set you back about $7000, just for the parts!
3) The idea is to replace the coolant before it goes bad to provide continuous protection.​

If you can do this DIY, which it seems you are capable of, this becomes a relatively cheap maintenance procedure.

 

Besides the issue about using the correct coolant, which has been beaten to death:

1. Did you check the fluid level in the radiator? If not, I suggest you do that now. It is necessary to remove the large black plastic panel over the radiator for access to the radiator cap.

2. If you find that the radiator fluid is low, you need to look for the leak. The most likely place is at the engine coolant pump bearing which will weep out fluid. Look for a pinkish residue on the inside of the pump pulley and on the air conditioner compressor housing. In very bad cases fluid will also spray upon the underhood insulating pad. If you see this, replace the engine coolant pump (and serpentine drive belt while you are at it.)

3. Toyota SLLC has a service life of 100K miles when factory fill and 50K miles for subsequent changes. When I've changed the coolant I've found that the old coolant looks perfect. Hence I personally don't think it is necessary to change the coolant more frequently than the interval prescribed by the maintenance schedule.

 

Perhaps this is a dumb question, but why would the radiator level be low if the reservoir level is ok ?

 

An excellent question. An owner might reasonably think that if the overflow reservoir has some fluid within, then the radiator must be full.

However it turns out that when the engine coolant pump starts to leak, some air may enter the coolant system. Once that happens then the reservoir will not replenish the radiator because the radiator no longer will have a partial vacuum to suck fluid from the reservoir.

Hence if there is any indication that the engine coolant level has been dropping, a diligent owner should check the radiator as well as the reservoir to avoid adverse surprises and permanent damage associated with engine overheating.

 

At less than 10 PPM of silicates, Zerex Asian has an inconsequential amount. Toyota LLC and SLCC probably has a similar amount but does not list it.

On that account, Zerex Asian would be just fine.

 

My conclusion as well.
I buy 6 gallons at a time from zorotools.com for about $70 (S/H is free.)* Super convenient, no trips to the dealership or store, and less expensive

IIRC, Napa also sells this coolant for ~ $14 a gallon + tax.

List price is $14.32 a gallon, but I have always been able to find coupons on the internet that take off another $15 - $20. The last time I bought a carton I paid $66 for 6 gallons; today it would cost $70 for 6 gallons.