I have a 1992 SC400 and my radiator broke about 2 weeks ago so I bought another one from Rockauto and installed it.
Next I wanted to drain and flush out the green stuff that was in the system.

To drain and flush the system I did this:
1.) Drained system through radiator drain plug. I couldn't find the right or left plugs like in this tutorial (http://www.lexls.com/tutorials/cooling/coolant.html).
2.) I added a Prestone radiator flush I got from Walmart and followed the instructions. I let it run and drove around for about 10 minutes to cycle it through the system. Then I realized I didn't buy enough Zerex Asian (Pink) so I waited until today to finish drain+flush..
3.) Today, I drained the radiator with the radiator drain plug and then turned the car on to help flush any extra stuff on with the heater on (based on other threads and instructions I've read and watched).
4.) After draining it out I added water through the fill hole by the thermostat and let it drain out of the radiator drain plug.
5.) I added some distilled water and closed the plug and radiator overflow tank (aftermarket) and let the car run for a few minutes with the heat on.
6.) I drained the system again and just tried putting a shop vac on the drain plug to try and suck whatever was left inside. The liquid was pretty clean, I would say a very very slight green but definitely not close to the normal green antifreeze look.
7.) After draining the system I added the Zerex pink and this is where I'm having a problem. I only was able to put 1 full bottle and then about a half of another which is only 1.5 gallons but from what I've read in (http://www.lexls.com/tutorials/cooling/coolant.html) it should be 2.8 gallons. After filling it with the car on and heater on and radiator reservoir cap off, I saw some air bubbles come up. Then I ran the car for a little longer to see if the coolant would go down anymore and it didn't, so I took it for about a 5-10 minute drive around my area and came back home to see that the little gauge on my aftermarket reservoir shows the reservoir is about half full. The heat works so I'm guessing the car runs OK. It's not overheating which is also a good sign I'm hoping. I'm just worried that if there is water in my system that it could mess up the 50/50 ratio. I'm also worried that if I have some of the green stuff left in there that it would turn into a jello like substance and mess my car up.

My questions are: Did I not drain the system out all of the way? Could there still be water in the system? If there is, how come when I put the vacuum on to suck out any extra fluids nothing came out? Should I wait a bit for my car to cool down and keep adding some?

Thanks for the help!

 

So heres my take since no one else bit....If you arent overheating, you are probably ok. You can always lift the front end up off the ground while the rear is on the ground and try to bleed the system of air again if you are really concerned. The 1uz and 2jz both have issues where the highest point in the system is not the radiator thus lifting the front to make the radiator the highest point.

In terms of the water to coolant ratio take a cup of 50/50 and then take a look at your reservoir. Do they look pretty close in terms of color and opacity? If yes then dont worry as all the coolant is doing is modifying the freezing point and adding some protections/lubricants for the pump. Getting close to it is good enough. yeah yeah yeah im sure there are many that will state 50-50 is a must, but i have yet to see a car have a problem from the mixture not being exact. Its always something else that is the problem; air in the system. failure of a gasket, clogged passage way. etc.

In short, having close to a 50-50 is great but being 60-40 or 40-60 shouldnt hurt anything as a daily driver. Good work on replacing the radiator!

 

After reading what I wrote I guess I didn't mention that the front end was already lifted. I left it lifted after I installed the radiator so I could open those two plugs on the engine block that I couldn't find and just make it easier in general to work on.
This aftermarket coolant reservoir has a clear tube gauge on the side and so far it looks as pink as when I pour it out of the bottle. I have been driving the car pretty much normally yesterday and today and before I drive I've been popping the hood to just make sure everything is still secure (I had to make a bracket for the new tank since it's kinda big) and nothing is leaking. I check the temperature needle while I'm driving too and it is slightly above the middle of the gauge. I think before it would sit around there but I can't remember for sure.
After driving it to work today I'm confident everything is OK. I was considering taking it to a shop to get it professionally flushed but since it never really gets cold here in Vegas I think I'll be all right. I was worried that the green stuff would mix with the pink, I heard it turns into a jello-like substance and overheats the engine.

Thanks for the help though, I really appreciate your input!

 

You're welcome, glad to hear you're feeling better about the situation! Now go enjoy not having to worry haha. As for the buildup from mixing two types; with how thorough you did the process I would highly doubt you'll see anything of measurable magnitude.

 

i've read somewhere our engine blocks have drain plugs for coolant. i don't know if its true because when i bled mine, i only got about 1 liter when swapping my blown radiator unless it leaked out days before.

 

Yeah I couldn't find them. I tried looking on the passenger side following the guide but couldn't locate the plug nor the bolt. I've read that other people couldn't find it on their blocks either.

 

The 2JZ motors have a coolant drain on the block on the exhaust side between cylinder 5 & 6. But in a typical drain, flush and fill you won't need to access this. I don't know where the drain is on the UZ motors but I would assume the same principles apply. As long as the car is level, about 80-90% of the coolant will drain out via the radiator. It just takes a while and you will have to have the upper radiator hose disconnected to let air get into the system

 

vipsoarer is correct when he suggests raising the car as high as possible to get the air out of the system. These cars are terrible at getting air trapping internally. Either in the heater core or somewhere else in the blocks. The only way to properly bleed the inline 6 motors and the xUZ v8s is to jack the front end so the tires are roughly 12in off the ground

 

I think I jacked the front up about 10-12 inches, it was the max my jack could raise the car up.