Generation 3 Coolant change

hi

Hope this will help

 

Wow, I just read each pdf...I guess I'll save some money for when that day comes! With the recent inverter failures reported here, I would not want to chance doing it wrong.

 

The coolant is recommended to be changed at 100k, not necessarily that's the exact time you need it done. If I were you, I would complete my "long trip" before changing out this fluid. Just so you don't have any issues from the coolant while you're on your trip.

 

Thank you for this valuable information !
However, I would agree on not doing this right before a trip as that may increase the chance of a mechanical problem rather than decrease it. (E.g. Slow leaks)
I would do this when I could put the Prius through several short daily use cycles and keep an eagle eye on the fluid levels for a week or two.

(Principle is from private aviation where a surprising number of mechanical failures occur just after maintenance.)

 

Coolant question for the assembled gurus here ....

I have a 2013 Prius Two with 84,500 miles. The engine coolant is due at 100k, but with a lot of extra (quarantine) time on my hands, I figured I might as well update it now.

Nuts About Bolts and others on YouTube have provided excellent videos. Many thanks for those. Member Mendel Leisk often posts pieces of the official Service Manual -- MANY thanks for that. I saved the how-to's for coolant, inverter coolant, plugs (just did those), brake fluid and pads, etc.

My question: all the videos omit the step of draining the cylinder block. The service manual has artwork that is NOT helpful in identifying the drain plug and air release valve. Anyone have good photographic reference for the valve and plug?

Secondly, I am not understanding the service manual instructions below. What the heck HOSE are we talking about? It just appears out of the blue with no prior reference in the instructions.

(d) Connect the hose to the air release valve.

(e) Loosen the air release valve.

(f) Add TOYOTA Super Long Life Coolant (SLLC) to the reservoir tank filler opening until coolant overflows from the air release valve. Then tighten the air release valve.

 

The "hose" I believe is just a drain hose, to avoid a mess. I'm not 100% certain, but believe 5/16" ID is about right.

I will do the engine block drain (this fall I'm due, by months). I've heard here it's pretty much a waste of time, not much comes out, but gotta see for myself.

It's on back wall of block, up fairly high, towards passenger end. IIRC it's a smallish set screw, and directly below is drain spigot, probably 5/16" OD again.

If you raise car and take off engine underpanel you can see/reach, barely.

I'm also thinking to pull off the lowest exhaust heat recovery coolant hose, see if I can drain a bit more, at least the once.

 

Btw, a 2013 probably doesn't have the air release vent

 

I drained radiator at 115K when I bought my Prius, and again at 150K when I did EGR cooler, EGR valve and intake manifold. Both times just drained the valve on bottom of radiator for 30 mins, closed valve and filled up the tank under the hood when finished. Ran car for 10 mins, checked level, then went on a 30 min drive and added coolant to top level of tank. Has not changed level since.

 

I'm getting ready to do this on my Prius. Do you happen to know if the 2015 gen 3 has the air release valve? I feel like using them makes changing the coolant much easier. Thank you!

 

Not sure, but believe it's only on 2010~2012. IIRC @NutzAboutBolts reported he doesn't have on his 2012, and I doubt they would bring it back.

Not sure why. A little voice in my head says maybe it wasn't effective, just due to the nature of the Prius coolant plumbing, it wasn't allowing air to escape, so they eliminated it? Or maybe just cheaping out, though I can't see it saves anything to speak of...

I'll be doing a coolant change this fall on our 2010, and will definitely open that valve when filling, see what happens, if there's air flow during refill.

All our Hondas had a vent. Last time I did a coolant change on a Honda, I had the presence of mind to hold my hand over the (opened) vent while pouring in new fluid, and could feel a real rush of air as I poured.

It'd be crazy to think that amount of air is bottled up during the fill process, due to lack of vent.

I would recommend for you (assuming lack of vent on your model year), to pull off one end of coolant hose atop the EGR that pushes onto the black gizmo there (believe it's temp sensor?), then start pouring, and feel if air is coming out. If you're feeling no air flow as you pour, maybe it's not needed to disconnect hose, and the vent was ineffective. But doesn't hurt to try.

Please post any observations; would be good to know.

 

I'm thinking to pick up some 1/4" ID surgical rubber tubing for drain purposes. It's very flexible, has no "memory", and the smaller ID will make for positive/secure connection when pushed onto the radiator or block drain spigots. It's readily available at most hardware stores.

 

The other day I spent a few seconds looking for one but didn't really try too hard. Mind you I am an amateur wannabe mechanic. In all the tutorials I've seen, there was no mention of an air bleeder. I honestly didn't even remove the windshield cowl or engine cover for a better look. My other Toyotas I've had currently and previously(Sienna and Camrys), all had bleeders.

 

From here:

In my 2010 Prius is there but I didn't use it when filling coolant.

 

A white peace of plastic on the top inicates it's a bleeder. It's knurled for gripping, and IIRC has a slot across the top (for a screwdriver). Without cowl removal it's a little buried, but visible.

 

Thank you for the info. unfortunately, my 2015 gen 3 Prius does not have this. I've seen the tutorial in the forum and nutzaboutboltz videos. I'm sure it'll go perfect.

Over the next few weeks, I'll be replacing all the fluids in my Prius and sienna (along with a few other maintenance tasks)

 

"... drained radiator at 115K when I bought my Prius, and again at 150K when I did EGR cooler, EGR valve and intake manifold."

How dirty was the EGR cooler + valve and intake manifold?

I'm about to change engine coolant at 84,000 miles. Figured I'd do the EGR and manifold work since I can get all the coolant out of the attached lines there. But I'm wondering if it's too early for EGR/manifold cleaning at 84k?

Last year I put in new inverter coolant, transmission fluid and brake fluid at 80,000 miles. Just did the plugs a few weeks ago. That's all due to the age of my Prius (2013), not the mileage or Toyota specifications (I live in Florida and drive a Burgman 650 scooter most of the time; probably don't put 3,000 miles on the car in a year). If I did maintenance by mileage, I probably wouldn't hit 150,000 until the year 3000 arrived.

I like to keep up on maintenance but I don't want to be overzealous if it's overkill.

 

EGR cooler was pretty clogged up, EGR valve pretty dirty, intake manifold was pretty oily. Time is a factor for me, so I bought a new cooler, valve, manifold (newest revision) and EGR pipe to ensure I could get back on the road quickly. Also installed oil catch can at that time. Car runs great, does not use any oil or coolant. Couple teaspoons of fluid in OCC every couple thousand miles. And I have backups for EGR system, nice to have, especially the spare cooler for next service.

PEH

 

"I'm wondering if it's too early for EGR/manifold cleaning at 84k?"

I answered my own question by doing the easy work first, cleaning the mass air flow sensor and throttle body. Both in like-new condition at 84k, so I will hold off on the EGR pipe, manifold, etc. The car has been garaged and driven gently. No worries.

One small hiccup (also known as "operator error" ;o). The yellow "check engine" symbol appeared after I did my cleaning. 84,000 miles and I've never seen the light, so I knew it was related to my work. Went to Auto Zone and used their OBDII to erase the codes but two stubbornly remained, P0102 and P0113. The 0102 code relates to the mass air flow sensor. "Did I kill it while cleaning it?" I wondered.

I drove home (now noticing a sudden loss of power when I hit the gas pedal hard), opened the hood and retraced my steps. Pulled the MAF sensor and it looked perfect. Started to remove bottom of the air filter case to check the hose connection below and ... voila. I realized I had not re-connected the MAF sensor to the engine! Of course there would be a code. I made it inoperable (It was late. I was tired).

I made the connection, started the engine (five times to make a code disappear) and the cursed yellow symbol vanished.

Sometimes I'm as wise as the ages. Sometimes I'm dumb as a tree stump.

 

Appears the 2011 I was asked to help with doesn't have the Air Release Valve (shown in bad photo attached), has some other strange almost similar looking junction. Think might put on mine, 2013, so has when I do the change.