2012 4.0 Full Coolant Swap

So, I'm fairly mechanical, but made the mistake of taking advice from some in "parts"...
My Tacoma just hit 100k and I wanted to swap the coolant.
I drained the radiator and overflow tank, ran distilled water through the engine, drained and added new coolant....
Noticed it only took 1 gallon when it should have taken just over 2....
Already trashed my back, and not really feeling like go after whats being a real pain in the a** getting to the 2 plugs in the block.
Looks like I'm doing it all over again....
With my old vehicles, I'd just drop the lower hose, drain all I can, then run the engine about 20 seconds and let the water pump get the rest out....
Is that an option here?
Thanks...

 

the option is to do it all over again IMO, this time draining the two ports on the motor AND flushing the heater core

 

I just did this on my truck yesterday which has over 140,000 mies on it and was never changed by previous owner. It can be somewhat of a pain getting to the engine block drains until you figure it out. However I finally figured I can access the one on the passenger side with putting several 3/8" dive extensions together and feeding it in the wheel well with a 10mm socket. Not bad at all. The driver side can be accessed from above the engine but you kind of have to get the socket on it by feeling for it under the exhaust manifold if you are going to do that. I was able to view it from the wheel well and get a socket on it from there. Then I went to the top of the truck under the hood and attached my ratchet wrench with 3" extension on it to it to turn it. I dropped over a gallon of coolant after I had already emptied the radiator by doing this. I don't know if I needed to or not but I also removed the thermostat to get good flow to the heater coil with the radiator flush since it is a little cooler this time of year. I will drive the truck a little more today and drain it and put the new coolant in it.

My OCD takes over when I work on stuff and I usually end up leaving no bolt unturned. When I recently adjusted the valves on my 2006 Honda Odyssey with 275,000 miles, I rechecked them 3 times before I put the motor back together, LOL!

 

Mikkydee, thanks for your input, and taking the time to write that all out.
I will go that route if it's my only option...

What I'd like to figure out, is if anyone has anyone ever tried this method, and how did it work out.

 

if you cant get the engine block drains open it will still be GTG, theres only a few more ounces in there, once you replenish it with more new coolant those few ounces will combine with the new and not amount to anything, I would just leave it as is.

 

When I did my drain/fill I got LOTS more coolant out of the block drains than the radiator.

 

I have 160K and never done it. Prob should but the coolant is still pink, drives fine

 

Does anybody have a picture of what these drain plugs look like and there location on the 4.0 engine ?

 

This vid help me find mine https://youtu.be/U08U9Vk7N7g

 

I also got more out of the engine block drains than out of the radiator itself. I had over a gallon drain out of my block after I already drained the radiator

 

update: I meant to mention that I intended to drain the cooling system and refill it with distilled water. Then run it for a while and drain it again before filling with the Toyota coolant. I do this on my flushes to be sure I get all the old coolant and the radiator flush additive completely out as well before I replenish the system with the coolant. This assures a good flush and complete removal of old coolant and radiator flush additive. Never use tap water in your cooling system even to flush it.

Removing the thermostat may not have been necessary but in my mind it assures a good flow through the heater core to clean it well also. Probably if it had been hot here this time of year I wouldn't have done that because I figure the thermostat would fully open.

 

Well, I figured I try to get to the engine block drain points.
Damn.
Here's my step by step.
You need a 3/8" inner diameter clear hose. This slides on the nipple under the radiator, and on the engine block drain nipples (the driver side one didn't stay on as well as the passenger side)
Make sure engine isn't very hot of course, and remove radiator cap.
Remove skid plate, it's only 4 bolts (12mm) and it's easier to turn the petcock.
Attach hose to nipple under radiator, on driver side. Turn petcock (its difficult, and feels like plastic so be careful)
You should get about a gallon drained here. Close petcock.
Remove rubber hose going from under radiator cap to over flow tank. Attach your hose to tank nipple and siphon it out (it pulls from the tank bottom) replace hose.
Now, for the engine block.. Crawl under truck behind passenger tire. Look for 10mm bolt with nipple under it (under exhaust manifold)
Attach hose to nipple and fashion a dump container (just over a gallon)
Turn bolt (10mm) counter clockwise until fluid starts coming out. When it stops, snug it back up.
Ok, now, the driver side one is a ROYAL PAIN IN THE A$$ TO GET THE HOSE ON!
It's under the front most exhaust manifold bolt, I was able to turn the bolt from above.
Here's the thing though... After almost an hour to get it on there, only about 6 oz of coolant came out that side!
Start truck and immediately start dumping 50/50 coolant into radiator until full. Turn on heater. You should (hopefully) see some bubbles while it's burping. I found it helpful to move the truck to a position where the front is elevated at that point. Let truck reach normal temp, top off radiator, and fill to the low mark on the tank. Once the engine is cooled, fill the tank to "full"
Replace skid plate.
Total coolant capacity is just a smidge over 2 gallons.

Disclaimer: I'm not a professional, and I'm just sharing my experience in case it could help someone.
Sorry if I left anything out.

 

yes theres only a few ounces of coolant in the block itself 6 ounces would amount nottoo much once you added the new stuff, people saying they are getting gallons out of the block are lying to you, most of the remaining coolant after a radiator/block drain is in the heater core, Toyota dealers will just drain the radiator and replenish with new fluid, if your old coolant looks brown or green and not the pink then you need to flush the system

 

I've never drained the block. But I have done 3 radiator DAFs. In my opinion if you do it early...say 50k miles, the occasional DAF is all you need.

Here's a couple of tips. A 22mm socket fits over the draincock. Makes it easy to open and close it. Just be careful tightening it.




Also...Toyota SLLC is good stuff. But it's not magical fairy piss. Our rigs call for a silicate free P-HOAT formula. You can find those requirements with Valvoline Zerex. It's even pink to perfectly match the OEM juice.

Best part? $13 a gallon at Wal-Mart.

 

Good write up on the flush and fill, It looks like if you want to save some time go to the passenger side drain plug
after the radiator is drained and leave the driver side alone. Just keep the interval on flush and fill lower say 50 K miles.
makes perfect sense to me. All good advice on this. Great thread.

 

drivers side drain plug

 

I haven't read anyone on here that said they got "gallons" out of the block. I got over a gallon out of the block which was more than than I got out of the radiator. Over half of the capacity was still in the system. In fact, I didn't start the job thinking I would drain the block. But since I got less than a gallon out of the radiator I decided I needed to in order to get out the large amount of coolant that was still in the system.

On another note, if you have a lot of miles on your coolant it actually can become acidic and contribute to corrosion in the system. You need to be sure you get it all out. Color is not necessarily an indicator that your coolant is still good. There are several tests you can do to check the efficacy of your coolant. A good test actually uses a voltmeter. Vids can be found on youtube to show you how. Also you can use the small testing "dropper" devices sold in auto parts stores to give you an indication. But it is always a good practice to change it out according to the recommended service intervals even if it still has some life left in it.

The coolant on my truck actually looked very good, virtually new. However when inquiring from the previous owner I found out he never had it changed or flushed in 13 years and 140,000 miles.

 

@mikkydee

It can be PITA for sure. That's why anytime I see a thread about coolant I post that.

 

great info on the 22 mm socket fitting the radiator petcock. I fought with that thing for 15 minutes with a pair of pliers trying to get it open. And another 6 or 7 minutes trying to tighten it back up.

update:I didn't have 22mm socket for the radiator petcock but a 13/16 SAE fit perfectly.

 

yes that one on the driver side is ridiculous to get to. I had both sides open and draining at the same time so I didn't measure how much came individually out of each side. But more definitely came out of the passenger side drain.
Were you able to get the socket on the driver side drain from the top of the truck? For the life of me, I could not. So I ended up getting the socket on from the wheel well and then attaching the ratchet to the socket under the hood from the top. That way I could see where to attach the rachet to from the top.