I am down a coolant flush and have had some unexpected issues.

The first drain of old coolant only got out 1.5 gallons. The 3RZ should hold 11 liters or 3 gallons, so I’d expect to drain at least 2. I was facing down a 2 degree incline.

So after refilling with distilled water I moved the car so that it was facing up slope so water in the radiator would flow towards the drain on the radiator.

I let the vehicle idle with the funnel in place to add water as air came out. I got up to normal temperature, and turned the front heating on, which shot out hot air. Then I turned the rear one on, and it felt nice and cool, no good. I tried turning the front one off, changed the fan speed, nothing worked.

I’m draining the first flush and will refill it for a 2nd go around. I want my rear one to blow hot so I can get the old fluid out.

Any idea how to get my rear heater blowing hot? It worked 5 months ago, but I do remember it taking a while.

Is it better to have my vehicle facing up the incline, or facing down?

Update: I took the car for a drive with pure water, now the rear heater is working really well. I greyed out what is no longer a problem. I still don't know why my 4runner isn't draining all the coolant, apart from a 2 degree slope. Anyone know if it's normal to only get only 1.5 gallons out of a 3rz with rear heat?

I'm guessing it's hard to drain the fluid from both heater cores.
You might have to fill it, drive it with both heaters on max heat and then drain.
Might have to repeat.

Did you happen to remove the thermostat while doing this flush?

As your engine block maybe holding the missing coolant. As if the thermostat is cold and closed.


You have air bubbles hence why you rear heater isn't working at the time. You can see it's up on the top where it hooks into the system. So you going to have to pressurize the system and get all the air out. Get the system full of water and flushed good.

Then put the coolant back in and run both cores on full heat to flush out the water and get the coolant back in its place.

This is mostly done with the thermostat out to let everything flush well.

Sent from my SM-A536V using Tapatalk

I got the heater working, it works better than before.

I didn't remove the thermostat, but I got 3 flushes done when it should of been opened. I'd fill up with distilled water, get up to operating temp, turn on heaters, wait for bubbles to stop, then immediately drain the still hot fluid.

I never got the water to clear, more of a faded yellow color. I would of liked it to look more clear, but I used all 6 gallons of water I had. It did look clear when draining out, but it looked yellow in a container. I looked it up and orange can be mixed with pink (supposedly).

The Toyota maintenance guide says to replace coolant every 30k miles. Does that apply to the Super Long Life pink coolant?

Super long life is 100k mile coolant. The other pink new stuff I believe is 30k mile coolant.

Sent from my SM-A536V using Tapatalk

I read that the pink coolant lasts 100k or 10 years from factory, then 60k or 5 years after that. Anyone getting those kind of intervals out of their coolant?

The Toyota red doesn't last as long

I read that Toyota says to use the interval specified for the vehicle, and not go by what's written on the coolant. So if you're putting 100K coolant into a vehicle that had 30K specified, stick with 30K changes.

The longer drain interval is only for vehicles that started with Pink originally and never had anything else in them. Use the Red interval - but you can use pink for the easier (non-)mixing if you want.

-Charlie

Yes, I get that long of an interval. My 5 years are up so it's getting a coolant change as well but if I'm being honest the coolant looks as good as the day I put it in. There's rust inhibitors that wear out though so I don't want to push my luck.

The block has a drain plug that you'll need to remove in order to flush it all out. Or do the thermostat/lower radiator hose. If you have the rear heater you have more fluid than those without it equipped.

Ah. You go with a 5 year interval changes. Not a bad idea. I mostly watch the coolant color.

If folks are concerned with inner rust. Evaporust makes a product that you can mix with distilled water for a day or so that eliminates all iron and aluminum rust in the coolant system.

This is good for an engine that been sitting around not hooked up for a while.

Sent from my SM-A536V using Tapatalk