Notes on changing the engine coolant on a gen 3

The repair manual says to also remove the "cylinder block drain cock plug". It's around the exhaust side of the engine, about halfway up, on the passenger side. That said, I've heard precious little comes out. I'll give it a try, when I get there, see what happens. I know with Honda's there was always a deluge when the similar bolt was removed.

Did you do the "inspection mode" thing, warm up the car and keep topping up? @NutzAboutBolts video shows that I think?

 

Easier than changing brake pads lol

 

Yeah, I've yet to do a Prius coolant change. Over the year with honda it was basically:

1. Pour in what it'll take (at the radiator cap, mia in the Prius), with the vent spigot open (there is one on the 2010~2011) untill coolant starts coming out of it.

2. Shut the vent and keep pouring till it's up to the neck. Fill overflow about halfway.

3. Start the car and let it run with radiator cap off (again, mia on the Prius), and stand at the ready with a baster and some sort of small container.

4. As the car warms it starts burping at the radiator neck (did I mention the Prius doesn't have this, lol), and the level will tend to go up/down, mostly up, so stand at the ready with the baster, to avoid overflow.

5. Carry on untill the cooling fan has come on twice, shut it down and ensure the overflow bottle's on the full mark, ditto for the coolant in the radiator neck (you know), cap the radiator.

Oh I do that every oil change, 15~16 times by now, and maybe 4~5 other times, for various forays. Always carefully pry the plastic fasteners out, and wash them free of grit before reinstall. I think I might have broken one in all that time. I find that "flap" way to fragile/brittle, want to keep the whole thing intact.

 

You can get the coolant online w/ ship for bit over $20 bucks.

I just do a simple refresh - inverter as well.

 

Checking my receipts: in April 2015 I purchased a 4 liter bottle of Toyota Super Long Life Coolant for $19.14 (CDN), at a dealership parts department. In Canada it's 55% concentration, comes in a 3.7 liter bottle, basically one US gallon.

 

"But wait! What is this hole directly underneath the radiator drain spigot? I peer up the hole, and there's the spigot! Now, if only there was a bigger hole I could get my hand into and reach around for that spigot. There is! ...The engineers knew their stuff, the manual writers didn't."

This is true, and thank you to Boffin for sharing it. Made my work much easier this morning.

I changed the coolant on my 2013 Prius and didn't need to remove the large plastic cover under the engine. I snaked a plastic tube up to the spigot, reached through the larger hole mentioned above and turned the yellow valve counter-clockwise to drain. Easy peasy. Photo with the yellow valve shown is what you see if you look up into the hole.

For the oil change, I was very wary of working under the car. In this case, I built a ramp of 2x3 pieces of wood screwed together, drove the car up the ramp, jacked it up to place jack stands behind each tire, then used a third jack in the foreground under the main jack point of the car. Three levels of protection; each can hold the car up on its own. I felt quite secure.

As it turns out, you can reach everything you need without really going under the car. The coolant spigot and valve are near the front of the car, in a straight line forward from the steering wheel. The oil change door swings open and if you bungee it flat against the bottom of the car (use the front grille), everything is reachable from the "northeast" corner (front corner on the passenger side).

 

i take the whole cover off pretty much any slow afternoon. Then just lie under there. Meditate.

 

"Then just lie under there. Meditate."

Ha, as the coolant trickled down through my plastic tube, it crossed my mind, "It's kind of peaceful down here." Had to keep a little attention focused on holding my tube in place, though, or the garage floor might have turned a lovely shade of pink.

 

I've scored a little over a yard of 1/4" ID surgical rubber tubing (it was the end of a spool, covid times at the hardware store, I got it for the cost of a foot. Not my foot...). I figure it'll push on securely to pretty much any spigot, and it's super flexy too, and no memory: goes where you want.

Planning to do the deed this fall, going to see if anything comes outa the block drain too. At least the first time: I've heard nothing much does come out there. However, it's been reported close to a quart drains from the exhaust heat recovery. Hopefully not by you in another thread: my attention span isn't that hot.

 

You and your large piece of stump get quality bonding time .

Maybe Mrs. Leisk appreciates it too.

Whatever works in the end .

 

Did anybody ever find the engine drain cock? The procedures I've seen just drain the radiator and that is wrong. Thats not a coolant flush. On a 1uz,2uz,3uz if you don't hit the block drains you will only drain 1/4 of the coolant lol.
The inverter flush looks straight forward though.

 

Yeah I found it. I drained the radiator first, then raised the car, took off the engine under-panel, and the aluminum metal shield just aft of that, reached waaay up, to right/back face of engine, pushed a tube onto the spigot, opened the valve, and got maybe 1/4 cup of coolant. If that. Don't waste the time and effort.

What motivated me was previous Honda experience: removing the engine block drain bolt always resulted in a deluge.


You might want to try pulling off one of the coolant hoses on the exhaust heat recovery system. That's NOT noted in the Repair Manual instruction, but seems like it would be fruitful. I looked at them, but chickened out: they looked formidable, and I figured let sleeping dogs lie.

 

I agree i was gonna say wow that engine drain is way too high! EHRS hose is just normal hose so I'll probably just use some hose pliers and twist it a bit to loosen it up and get it off. I bet if I do all of them I can get probably all of it out. I'll have to record how much comes out.
I went on the good ole internet today and half of the videos said to use the old red coolant and just drain the rad so i bet a lot of people are doing this. yikes

 

i think the consensus of people who've tried is that the block drain isn't worth the hassle. You'll never get all the old coolant out, anyway. That's why Toyota suggests shorter change intervals after the first time, to compensate for the residual.

 

The block drain is more for after they machine the block and clean it.
The only way to get all the used coolant, or oil for that matter, is to take the
engine aparts and run it through a parts cleaner.

It's not a Formula 1 car. It's a Prius.

 

Yeah i don't think they thought it out on this car. But when done correctly the block drains do in fact get it all out. no offense to anyone in here though, it just bugs me lol
i think the lower heat exchanger hose is just fine though for a good port to use.

 

Radiator drain IS the lowest point in the coolant system, and the best place to drain it.