16 year old coolant 179K miles Toyota 2.4l 2AZ-FE. A few questions about changing coolant.

Flushing a system unless there is something drastically wrong with the coolant is a waste of time and money. If you look up the factory service manual for your Toyota, Honda, etc you'll see the recommended coolant change procedure is just to drain and fill the radiator. Modern Toyota SLLC coolant is good for 12 years or 120K miles so changing ever 2-3 years is a little excessive.

Also I wouldn't really worry about swollen hoses on a 16 year old (2005) Toyota as it really isn't that old for the hoses to start failing.
 
Toyota SLLC is awesome coolant, I would just drain out as much as possible and add more magic pink juice (SLLC). Reminds me, I need to do my wife’s xB one of these days, now I’m up to 16 1/2 years & 115K, still looks brand new. I think I’ve added some once or twice…
 
Toyota SLLC is awesome coolant, I would just drain out as much as possible and add more magic pink juice (SLLC). Reminds me, I need to do my wife’s xB one of these days, now I’m up to 16 1/2 years & 115K, still looks brand new. I think I’ve added some once or twice…
I have some PEAK Global Lifetime 50/50 at home. Looks universal with all the flags on it.

Should I just get PEAK Original Equipment Technology Antifreeze + Coolant for Asian Vehicles - Red/Pink?
 
The thing is that hoses can be swollen and still look good until you compare them to a new hose. That and part of the swelling process I swear makes the hose a little longer too. When looking in your engine bay, your basis for comparison is going to be other swollen hoses.
You showed an image of two hoses, one swollen and the other not. I am supposed to disregard it. Again, it's your photo, am I supposed to not notice the difference?
 
You showed an image of two hoses, one swollen and the other not. I am supposed to disregard it. Again, it's your photo, am I supposed to not notice the difference?
The difference is usually not quite that extreme. Also, I made an additional post about how when you look around your engine bay even swollen hoses can somehow look better than they really are because if all the hoses are equally swollen your basis for comparison is going to be other swollen hoses. I'd have to think that hoses that are swollen get larger in diameter and length makes them weaker since (presumably) the hose itself gets thinner, or at least less dense.

Around 1.5 - 2 years ago I swapped out some ~17 and ~24 year old hoses (some OE Ford and some aftermarket Goodyear Branded) while I was doing a head gasket change. I was amazed at how much even the "newer" of these hoses had swollen when compared to brand new hoses. But looking at them installed in the car before the HG changeout, you would never know, as they looked perfectly fine. They mostly even looked OK from the inside of the hoses, but I'm not sure that I would trust hoses that old that were stressed out by a HG failure that leaked exhaust into the cooling system.

I know that cooling system hoses used to be a more regular PM several decades ago (like in the 70's), and that basically people stopped doing that. That's because for most people (maybe not BITOG types) coolant hoses typically outlasted their term of ownership of the vehicle. But if you are doing work on the cooling system anyway on an old car that already has high mileage and planning on keeping the vehicle for a while, it might be prudent PM, especially if the vehicle is still used on long trips.
 
Don't flush with anything. Just dump the old coolant and refill with Toyota brand long life coolant. I have 307,000 miles on my Tacoma, same water pump from the factory. That is all you need to do.
 
I wouldn't waste my time flushing anything out, just drain and fill. Done. Do it again a couple years from now if you feel the need. Unless that thing has a leaking intake/head gasket, letting some oil or coolant in there, or you're finding contaminants in the overfill tank? I wouldn't worry a bit about that coolant system being in need of a flush.

As for the hoses and thermostat? I wouldn't bother doing that either. I have NOT seen a blown hose on an engine in over 20 years. I don't know why...I don't know what they're making hoses out of nowadays, but whatever it is, it's good. And I have only seen a handful of thermostats go bad in that time frame, usually stuck open. I don't know if I'd bother, chances are the replacement aftermarket thermostat might be in worse shape than your 16 year old one. IMO.
 
Toyota Super Duper Effing Pink Long Life Coolant is some of the best antifreeze on the market. At $26 per gallon, it may seem pricey, but it isn't. Keeps you engine clean, thermostat and water pump working flawlessly. Like doublebase said above, blown hoses are almost impossible to find. Just put in the pink juice and walk away. You're done.
 
Toyota Super Duper Effing Pink Long Life Coolant is some of the best antifreeze on the market. At $26 per gallon, it may seem pricey, but it isn't. Keeps you engine clean, thermostat and water pump working flawlessly. Like doublebase said above, blown hoses are almost impossible to find. Just put in the pink juice and walk away. You're done.
I think I'll keep it simple and just top the coolant off, it's getting too cold to be wrenching on a car.
 
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I have never “flushed” a coolant system. Ever. Just drain and refill every 2-3 years with OEM coolant mixed with distilled water.
Many years ago a good friend who was a tech for GM and Nissan told me the same thing. I picked up that practice and have been doing it ever since, in healthy well maintained vehicles I bought new. It works quite well, my 88 E-150 radiator is still as clean as it was the day it rolled off the assembly line.

In October I did a drain and fill of our 2008 Liberty and the coolant that came out was as clean as the new coolant I replaced it with. The problem many people have is they change their oil and neglect the cooling system.
 
Hoses go bad if you get oil on them, or in them.

Had a saturn with a cracked head, oil intrusion to the cooling system. Fixed it, put it back together with the old hoses (minimum parts) to see if it ran. The rubber was a smeary, tacky mess and the top hose literally sweated antifreeze, like it was some wierd Reverse Osmosis membrane or something.

Many V8s have a hose that goes around and under the front crank seal and gets dripped on and softened there.

tl;dr you can blow a hose if your car's got problems.
 
If the previous coolant was Toyota OE fill and similar is used, I don’t see the reason for a flush unless the coolant’s conducting a lot of voltage. If you were switching colors or chemistry yes - but IME I switched a Toyota to Prestone and all I did was get most of the pink coolant out.
 
Hoses go bad if you get oil on them, or in them.

Had a saturn with a cracked head, oil intrusion to the cooling system. Fixed it, put it back together with the old hoses (minimum parts) to see if it ran. The rubber was a smeary, tacky mess and the top hose literally sweated antifreeze, like it was some wierd Reverse Osmosis membrane or something.

Many V8s have a hose that goes around and under the front crank seal and gets dripped on and softened there.

tl;dr you can blow a hose if your car's got problems.
Toyotas also use that the LC/4Runner/Tacoma guys call the hose from hell - it can be a small hose in an nearly impossible place to service or one that needs near complete disassembly to service. I haven’t seen a coolant hose run under the crank on Toyota V8s but in close proximity to a power steering or ATF line.
 
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