Coolant change

How many miles on your Prius?

Considered doing the egr circuit cleanse since you’ll be doing the engine coolant change?

The engine side coolant change is no problem but I’d have someone else there with you for the inverter coolant. That level drops quick.

Good luck and keep us posted .

 

I'd suggest having empty containers available for the old coolant that will let you compare the volume of coolant you drained to the volume you put back it. It helps you know when you're close to getting out all the air.

 

For the inverter shut the ice off once it starts and refill

 

, 85 v

Posted via the PriusChat mobile app.

 

just watch the videos and you'll be good. Nuts about bolts does a good job covering all the details.

 

There's an engine coolant drain spigot on the back of the engine. Very hard to see. The Repair Manual engine coolant change instruction says to drain this too. I've always drained engine block, on various Honda's over the years, and always got a FLOOD of coolant from the engine block. But from all reports here not much comes out? Anyway, if you're game, something to try. The one time I've been able to see this spigot, is by having the front of the car raise, and having both the engine underpanel and the NEXT panel aft removed: then you have a clear view of it. It's designed to push a tube on, and then you can open it like a tap.

Another place you can apparently drain some coolant: at the exhaust coolant heater mechanism. Pull off the lowest hose and let it drain.

For tubing to push onto the spigots (most necessary on the engine block drain spigot, since it's up so high), maybe surgical rubber tubing? A short length at least, with a connector to your vinyl tubing, since it's stretch, will easily fit a variety of spigot sizes. Also, check the diameter of the drain spigots in advance, so you know what to look for if shopping for tubing.

@Ragingfit 's got a short video here somewhere (also on his Youtube channel), I think in a nutshell he advocates when you're running the engine in inspection mode after the refill, unbolt the (refilled) reservoir and raise it up as high as the hoses will allow, tie it with cord to the hood latch, just to get some extra "head" on the coolant pressure.

Also, doesn't hurt to try squeezing/shaking the hoses a bit, might coax bubbles out.

And...: use the bleed bolt. It's the white capped, black-plastic gizmo, just above the EGR valve/cooler, when refilling the system. Leave it open as you pour coolant in, and feel: if it's working there'll be a gush of air as you pour in the coolant. I've never done a Prius coolant change, so am kinda curious if this is actually effective. If you use the bleed bolt, please comment how it works. It's only on 2010~2011, discontinues on 2012 onwards, not sure why.

 

I'm curious, on the engine coolant change repair manual what does Toyota mean when they say "bleed air from the cooling system"?

At this point according to the manual you should have the reservoir cap on and the air release valve closed so what exactly are you supposed to do?

 

I'm guessing that "air release valve", leaving it open during the refill, till a steady flow starts coming out. The document was published in 2009, and in 2012 model year they nixed that valve, not sure why.

 

They mention that in step F, then you close the valve. Then step L is to bleed the air after the coolant has already been filled and the engine is warmed up.

Can you use the air bleeder valve as a traditional bleeder at this point? (Open it then close it while the engine is running and warm)

 

I've yet to do this on ours.

 

how much coolant is required for both chambers - engine and inverter? In my area, Toyota Super Long Life Pre-mixed comes in one size only - 3.785 L

 

You'll need two bottles. From my maintenance notes, when I did both:

- engine coolant drain: 4.25 liters roughly
- inverter coolant drain: 1.5 liter roughly

 

From manual (sorry it's in Romanian but numbers are numbers ).


7.2l for engine and 2.1l for inverter.
When I did my coolant change I used 7.2l for both.

 

I followed instruction to open tap on engine block: difficult to access, and less than 1/4 cup drained; I wouldn’t bother with that.

On the other hand, there’s been speculation you could drain a significant amount (of engine coolant) if you pull off one of the hoses at exhaust heat recovery. I chickened out on that (they’re significant sized), maybe next time.

 

Thank you @burebista and @Mendel Leisk .

 

I have a few questions in my mind since this is going to be the first-ever coolant change on mine. (10+ years and 125,000 kilometers).

- Since the water pump in Gen 3 has a reputation for failing at around 100K, should I replace it as a preventive maintenance?

- Is it required to change the coolant thermostats too?

- The atmosphere here is generally hot and humid with summers reaching 45° Celsius ( around 115F). During 20 days of winter, it doesn't get colder than 10° Celsius ( around 50F). Toyota Super Long Life has antifreeze properties, something I doubt will ever be needed. Having said that, is this coolant good enough for the high ambient temperature I have mentioned? I understand that we are talking about engine operating temperature here which usually gets twice as hot during peak.

- Will there be any issue if Toyota Long Life Red Coolant ( 50-50 mix with Distilled water) is ever used to top up while the coolant chamber containing Toyota Super Long Life Pre-mixed Pink Coolant, if ever needed?

 

I believe I have found something interesting. An expiration date for coolant - 2 years from the date of manufacture on the bottle I'm about to buy.






I thought the coolant changing period was at least 5 years after the first change. If so, the expiry period of 2 years from production makes no concrete sense.

Maybe, the plastic container affects the coolant if stored inside for more than 2 years?

 

I don't know about a shelf life/expiration date on unopened bottles of SLLC, but the reason for the shorter coolant change interval after the initial coolant change is that you leave some old coolant in the heater hoses, and heat exchanger inside the cabin.

Posted via the PriusChat mobile app.

 

Expiration dates apply to how long before you use it.

Most of my engine coolant drain and fills were slightly less than 5 US quarts.

Measure what comes out, leave cap off as the engine warms up in Maintenance Mode, watch air bubbles after the thermostat opens as indicated by fluid flow from bottom reservoir hose, top off as necessary to the amount you removed, cap and drive.

No special bleeding but almost three quarts of old fluid remains each time. Even if you pull the engine it will still have coolant in it.

Best to change like this every 40k-50k miles- likely to reduce erosion of head gasket sealing material.