Would you use a radiator flush cleaner during your coolant flush?

I wrote a post some time back about the Toyota Red coolant. I have a gallon container in the garage diluted to 50/50 with distilled water. I did a radiator drain and refill last summer as a pm. Anyway, in that post I listed the temps and ratios from the container. I tested my diluted mix with a prestone tester at the time and it matched the chart for 50/50 just about exactly. About the hoses, the rubber ones can fail for many reasons, age being a big one, but if you have any oil leaking on them they will soften up like you wouldn't believe. I'll bet silicone is at least the same as OEM if not better. Good luck and let us know how it works out.

 

I drained mine, refilled with straight distilled water. Ran it a couple days then drained and refilled with straight distilled again. I drained again and then added six quarts of concentrated coolant. Then topped it off with distilled. I know there was still distilled water left in the block but it doesn’t matter. System holds 10 quarts, I put 6 quarts of concentrated in, between the distilled water left in the block, and what I topped it off with that added up to the other 4 quarts.

 

Gotcha. Sounds like your method is very similar to the one I mentioned in an earlier post. There is a pretty good write-up about the process I was going to use. Fortunately these trucks are pretty easy to work on - which is why I sought one out.

 

Thank you! That is good to know about the tester - I will report back next weekend when my radiator arrives

 

That seems to be about where I'm headed. Hadn't considered just straight distilled after the initial drain and then running it a few days. Doesn't seem to hurt given that there has been a few folks that have commented similarly.

Yea, 6 quarts (1.5 gallons) is where I'm headed. Nice thing is we are headed into summer, so I have time to get my ideal low point ratio dialed-in before winter roars it's beastly head again.

 

Guess I should mention just so nobody does it, don’t let it freeze when you have straight distilled water in there!

 

great point. Don't do it during freezing weather.

 

Figured that would be a very bad thing! Thank you

 

I've been so anal about fluid changes in my vehicles over the years that I have found that coolant system flushing is a huge waste of time. I've never seen anything come out of there and that includes back when they made "real" coolant flushing chemicals that really worked! Unless you've bought a used vehicle that has been abused I can't see the point.

 

I thought these flushes were basically just a mild acid that will dissolve small amounts of rust that have built up in the system. You can mix up your own mild acid using cheap citric acid powder.

Probably where this would help the most is in the small passages in the radiator, but if the radiator is old and original it's probably just better to replace the radiator with a new clean one and save the time and effort of trying to do flushes to clean the old radiator out.

The other place where the flush might help is breaking down any rust on the outside walls of the cylinders that could prevent efficient heat transfer away from the cylinders into the coolant.

I don't really see how removing any rust on the outer wall of the engine block or other places will have any impact on the cooling system. The point of the cooling system is to transfer heat from the cylinders to the coolant then from the coolant to the air through the radiator, so those 2 places are all that matters for the most part. (and maybe the heater core if you need a lot of cabin heating)

 

I suspect that with regular coolant changes per factory intervals there isn't any rust or corrosion that builds up at all in these new engines with the materials they are using in them. The cast iron block is really the only place you could get rust from. Everything else is plastic or aluminum.

 

As far as I could tell from the service records (and maybe I didn't look closely enough) the coolant hasn't been changed in this truck yet...which I find hard to believe. Hence why I'm just replacing the radiator and doing Toyota Red (it's running something green right now - what the PO had used in it). I also am running hotter than I'd like right now - by about 8-10 degrees so I'm hoping the new radiator and Toyota Red will do the trick. (Already have a new thermostat - had that done with the WP & Timing Belt).

 

In your case you may want to go through the hassle of a flush. Green doesn't go in Toyota's. Wise move using the factory red. That's what I do in mine. Many people out there think coolant is coolant. It isn't. There may be a green that works in Toyota's but I'd never take the chance. There are just too many "chemistries" as far as coolants out there in use today. I just pay the extra for the Toyota red.

Use a flush and then douche that thing over and over again with distilled water. Drain the block and everything else you can open up. It'll take you about a week depending on how much you drive it everyday. It might not hurt, being summer, to pull the thermostat while you're doing it, That's what I've always done when I do a real flush but I could be too anal retentive about still having the flush, or any trace of it, in my cooling system when I dump in the new anti-freeze.

Most of the flush products say to run them for a certain number of hours so you may want to leave it in there for a few days with distilled water. Once again, depending on how long it's run "at operating temp". It needs to be a operating temperature for the flush to work. Even with just plain distilled water high heat will flush a lot of crap out of there.

Believe it or not? That was the factory method for flushing the cooling system on the '73 Caddy I owned for 18 years. Cadillac said idle it and get it hot with just plain water. They said to even put cardboard in front of the radiator to increase the coolant temp. I don't know if that is wise with these newer cars made with plastic and aluminum.

 

Interesting! Yes, I think given the responses to this thread (thank you all whom have) I am going to do some variation of drain, flush w/ distilled, heat, repeat. Maybe take a lap or two up valley at 55 mph with just distilled and then come home 20 miles later and see what else I can keep flushing out.

I guess I'm trying to decide when to put in my new radiator (when it arrives and I begin this process this coming weekend)? Do I drain the old green coolant, flush once, then install the new rad? Or wait a bit longer? I have a feeling draining the old rad, then flushing once will be a good place to start with inserting the new rad then.

Thoughts?
Thanks!

 

I also don't know how hot my 2.7 is supposed to run but in the winter with the cover on the grill I still get down to around 173 degrees. In the summer I very rarely get past 188 or so. and that is only after I get off the interstate running at 80 mph onto a 35 mph street. That's understandable. It usually runs around 180 even at 80 mph on a 90 degree day. It never breaks into the 190's and I only got it over 200 one time when I was spinning up a really long steep hill covered in shale at 4500 rpm on a 100 degree day. I never did that again. That hill was probably a 35% climb. They have quite a few of those where I live so I stay off of them with my daily driver.

 

Since you don't know what's in there I'd flush it with the old radiator first. When it's clean then put in the new radiator. You could get lucky and find that there isn't really anything in there but I wouldn't install a new radiator not knowing.

There is also a block drain. I'd find it and drain the block through all of the cleaning.

 

I hope to get down to 175-180 degrees!! Time will tell. I look forward to the radiator replacement and flush this weekend

 

Makes sense. I appreciate your opinion

 

Shit, I hadn't looked where you live. I'm in Wyoming. I'm sure you can get down to 180 up there. Maybe 181 or 182 where mine runs at in the summer even on a 90 degree day at 80 mph.

 

I believe it! It's a solid hope of mine - I would love to be in that temp range - hence why I'm swapping and flushing. A new LCE 180 degree thermostat was installed last week, and that took 10 degrees off what I was typically running 198(!!!) degrees.