Advice on Coolant change

I was planning on doing a coolant drain and fill including the 2 engine block drains, after looking it over to game plan how to do it. I noticed the drivers side was replaced with just a regular bolt, no drain spout at all now. Took a bit to realize the dang thing was missing. I bought Toyota pink coolant to do the job, will that be alright to mix with what they used. (Pink also) and no clue when it was last changed. 100k on her now. I’m thinking I can just drain the radiator and reservoir and use a spill proof funnel to burp any air out. Guessing I can do this again to get mostly Toyota coolant in it, how many miles should I go if this is the route I need to go by or Is there any other way I should do it? Thanks in advance

 

If you drain the radiator and both block drains your gona get 95% or better out, if your concerned about it having different coolant in it put a couple gallons of distilled water in it, run it a bit, and drain it again before you put the new coolant in.
If your worried about sedement drain it, leave your drains open, pull the heater hoses off, and flush through the heater core both directions and through both heater hoses with a garden hose.

If you get it good and clean I'd go by Toyota's schedule of 5 years or 50k mi.

 

I highly recommend draining it completely....then just fill it with water, start it up and let it cycle the water all through....then drain and refill with your coolant choice....

Helps really get the old stuff out along with extra crap, also minimizes risk of issues with compatible coolants.

I've done that twice now with no issues even switching coolant types and colors....200k+ miles and no issues.

 

I think if it hasnt been contaminated, the 3 drains is enough. I'd call it good after that, no need to repeat.

If contaminated, I run it with all drains open and a hose puking water through the heater lines.

 

It don’t look contaminated at all, looks pretty clean imo if I had to take a good guess Toyota coolant was used since most of its service is from a dealership but doesn’t list coolant service on the carfax records so who knows. The 3 drains aren’t accessible the driver side brass drain plug is no longer there. It was broken off and replaced with just a bolt no drain spout. I can only access the radiator and passenger side don’t feel like messing with that bolt. Don’t feel to comfortable messing with the heater lines.

 

Pretty sure the block drains are tapered thread.
If you remove the bolt, you’ll need to apply thread tape or sealant to the threads when you put it back in.

I chose to NOT drain the block.
With my luck, they’d leak and I have a new problem to fix.
I just did a couple drain and fills.

However, drain the block is the best choice if you want to get them on coolant out as you can.

 

I only drain the passenger side, if anything happens, it's way easier to repair.

 

Im leaning on the drain and fills. If by chance the fluid is like zerex or something would the Toyota be compatible with it mixed and if so how far in between should I do the next drain and fill? 300-500 miles? just like get fluid mixed and drained again or is that a bad thing in so little time? I don’t wanna mess with either engine drain plugs/bolt now either lol my luck I’ll break the passenger side.

 

Then again should I risk draining the passenger side plug since it does hold more fluid, sucker does look in good shape maybe they didn’t mess with it after knowing what they did to the drivers side. Hmm

 

With drain and fills, you can drain and refill as soon as the thermostat opens.
Which is when the truck is up to normal operating temperature.

I waited a few weeks.
Only because I’m lazy, and didn’t want to wait for the truck to cool down 3x in a single day.
Is that lazy or impatient?

Again, it’s not the best way.
It’s not the most cost effective way either.

I’m not trying to sway you either way.
Draining the block is the best way.
I’m just telling you what I did

 

I was looking at that red Zerex coolant from Valvoline the other night. I'm going to drain and fill my 3rd gen and replace the hoses. I never pull freeze plugs/engine drain plugs as you risk stripping the threads. If the coolant drains clean from the radiator you really don't even need to flush; just drain and fill.

The Valvoline Zerex and Toyota coolants are already mixed 50/50, so if you flush with water and use either of those you'll dilute further. You're probably okay to mix the Zerex with the Toyota, but personally I'd do either or for piece of mind. Ya never know what ingredients manufactures use and there's always a risk chemicals won't play nice together. I'll bet they're very similar if not identical though.

Leave the heater on full blast while you're burping the system to circulate the coolant through the heater core and run the engine long enough so the thermostat opens and closes a few times. Add coolant as the radiator sucks it down. A 2 liter soda bottle cut in half or 2/3 and turned upside down makes a large/cheap funnel.

 

Think I’ll drain the radiator and try the passenger side drain and pray I have better luck lol and not mess with that bolt on drivers side since I’d get fluid everywhere anyways. Plan on doing it while truck is cold and jack it up a little in the front to get nose up to not let air in system. Drain radiator,reservoir and passenger side, tighten back up, refill coolant with spill free funnel attached, start truck up with heat on high? Or leave heat off? let it get up to temperature and watch/wait for bubbles to disappear, maybe rev it up to help or grab top of radiator hose? Then after no bubbles turn off, lower truck back down and replace cap, that sound about right?

 

I been where you are.
I even made a post about.
It’s worth reading

See post 14

https://www.tacomaworld.com/threads/radiator-petcock-question.633936/

 

Don't even bother with the driver side.

If you drain the rad and passenger you MIGHT get 1/4-1/2 a quart of coolant from the driver.

If coolant looks good when it comes out. I'd simply fill run, top off and call it good.

No use in flushing.

If you are so inclined to flush, DISTILLED WATER ONLY, no hose water

 

The block drains are there for when you have to change the water pump or stuff like that. I wouldn’t mess with them for a coolant flush. Block drains are actually little spigots here to avoid mess. You can put some small ID tube on them and only loosen the smaller (believe 10mm) bolt so it’ll drain. Don’t take out the whole plug from the block unless you hopelessly stripped the small bolt.

 

Or Irontite if you have crud in the heater core…. Either way gonna need like a drill pump or something because yeah, garden hose isn’t a great idea. Kinda defeats the purpose of doing the maintenance task in the first place.
#if it ain’t broke, fix it till it is

 

FIFY,

Heat on high if/when flushing the system and when burping the system after refill. This will circulate the coolant through the heater core and purge the air from the entire system. When you hear about cars with no heat it's sometimes due to a clogged heater core.

 

The only incompatibility issue I’ve ever experienced is with the brown dexcool type of stuff. I don’t know if color is standard across different brands.

If you’re concerned about incompatibility you could mix a little of the old coolant with what you intended to use in a small container to see if it turns into cottage cheese.

For fun you could perform an electrolysis test before draining it. If it fails you’ll have a better sense of accomplishment afterwards.

 

I believe that this serves no purpose on the 2nd gens as there is no valve that shuts flow on or off to the heater core. so coolant is always flowing through it.

 

So no need to turn the heat on when I do the drain and fill on the radiator?