Rust colored coolant flush??? (1 Viewer)

[nicholas]

I couldn't find anything in a search besides info about the rusty rear heater hoses, so here is my problem:

I have been doing a series of drain/fills on my rig with distilled water after doing the prestone/garden hose flush. I probably did the drain/fill/drain at least 8 or 9 times over a week long period because I ended up doing the tap water flush twice since it looked like the drainage wasn't completely clear.

Each time I did the fill/drain, I drained both the Radiator petcock and the engine block plug (I can literally remove/install the engine block plug with my eyes closed or in the dark), and I ran the engine until the brand new OEM thermostat was open with both the front and rear heaters running.

When I collected the water after the drainings, the first 6 drains had some of the notorious gray clay looking residue that settled to the bottom of the jugs over time.

However, the last few drains (after the second tap water flush) came out orange-ish and later had a rusty colored residue that settled to the bottom of the jugs which confirmed my fear that I must have rusted something in my cooling system.

I read in e999's writeup that he wouldn't hesitate to leave distilled water in a system for a few days to ensure a thorough flush, so I must have mistakingly figured that a week wouldn't be too much.

So my question is do any of you have any guesses what the most likely source of my rust is? My rear heater lines look ok from the outside, and I just replaced the PHH w/ silicone. The PO had the HG replaced by the lexus dealer about 40K/3.5yrs ago.

I'm worried that I just fubarred a perfectly good 1FZ. Can anyone calm my fears?

 

[nicholas]

Has anybody had this problem? I might add that this is not a case of mixing Toyota Red and Prestone green. I put in several flushes of distilled water and it came out with rusty sediment in the collection jug.

 

[gotmud]

I'm worried that I just fubarred a perfectly good 1FZ. Can anyone calm my fears?

I had similar problems on my '94. It took several flushes using 2 bottles of Prestone Super Flush before I got the bulk of the crap out of it. Even now, a year later, I still have a little bit of sediment. I just flushed mine again last week and see that I have what looks like little pieces of rust floating around. So far, it runs just fine and never over heats.

I'll flush it again in 3 months and re-evaluate.

BTW, don't worry about running just water for a while, you'll be fine. I wouldn't tow or take any long trips like that though.

 

[nicholas]

Thanks for the reassurance. I only filled/flushed then drove short periods (<7 miles) with straight water in the system. The thing that was weird is that the water drainage was clear in after about 4 or 5 drainings, but during the last set of drainings they started to get tinged with rust residue, but no gray clay residue. I guess I'll just keep up on the annual flushes, and not worry about it.

 

[mypancreasbroke]

Resurrecting an old thread, but I have been doing the flush/fill with distilled water for several days now. Just tonight out in a new heater valve and all new heater hoses up top, after having last week done new radiator hoses and thermostat after a good water hose flush. Feeling pretty good and confident I refilled with distilled water tonight and let the truck heat up, while running both heaters and looking for leaks. Finished the night off by opening the top of the radiator to check its level, and instead of nice clear water I see it is rust colored. Not as heavily as before, and looks lighter than my earlier flushes, but not clear water as I had hoped.

I planned tomorrow to do a final drain and finally fill with distilled water and antifreeze and button the whole thing up and feel confident in a job well done. But now I'm worried about more gunk in the system.

Around 225k on the truck and unsure of its history, though there have been lots of indications it has been pretty well maintained. Should I jus keep flushing? Or would it be fine to button up, drive for a few months, and maybe think about another good flush and fill after Christmas/early spring?

 

[Timpanogos Slim]

coolant flows through the block too, right? Iron rusts.

One of the major components of the coolant mix is corrosion inhibitors. with green coolant it is supposed to be normal to replace it every two years.

Red or pink coolant lasts a lot longer. It just does. Completely different inhibitor.

Prestone radiator flush is just a bit of trisodium citrate in water - a salt of citric acid that is slightly basic but is a good de-scaler. some of the others (liqui-moly for sure) contain a detergent as well, and running a scoop of dishwasher powder in straight water as part of the flush is something mechanics sometimes do in cooling systems that have been contaminated with oil.

I haven't done dish powder, but I did run some borax in water when i was cleaning out my rig's system. Unless I'm very confused, the effect of borax is to increase the capacity of the water to dissolve crud. Just like in laundry. Washing soda (sodium carbonate) has a similar effect.

As annoying as it sounds, I think what i recommend is that you just keep going. Maybe one more application of one sort of cleaning agent or other for 10 miles or so and after that just water.

And don't expect it to ever run completely clear. but when it's clear-ish, go ahead and go for whatever coolant you are willing to commit to.

 

[mypancreasbroke]

Awesome, thank you. I haven't used any cleaning agents or chemicals while flushing. Simply ran a hose and back flushed the block and heater cores, and drain and fills with distilled water since then. I seem to remember reading a lot of posts on here with warnings about cooling system cleaners and chemicals. but not sure. I do have head gasket paranoia and there's a voice in my brain that says introducing anything like that could cause an issue, but maybe a good cleaner would do my system well to really clean it all up.

 

[tominboise]

I think it's probably just flash rust from your block. I'd drain and fill with green and move on. Maybe replace it in a year or two. In the interim, don't open the rad cap. It will save a lot of second guessing. These things run all over the world with whatever the locals can find to fill them with.

 

[Marine7]

Tominboise is right on the money! I think that, here in America, were spoiled by these tv shows and magazines that show these trucks being worked on, and everything is sparkling clean.... you could eat off most the engines! However, after going to Panama, Guam and the Middle East..... where the Cruisers are actually worked to their limit, they find whatever "mud puddle" they can, and top the cooling system off! OK.... maybe I dramatized it a touch, but hopefully you get my point. Instead of trying to keep up with Extreme 4x4 TV (where I'm sure they get sponsor $$ from Prestone, and every other coolant mfg) or whatever tech article Four Wheeler mag (again....sponsor $$$) has going, just use your common sense. A 20-30 year old vehicle JUST MIGHT have a tinge of rust coloring to it, if it isn't brown and chunky... your fine. Check it regularly and ENJOY YOUR CRUISER! I know I do..... until someone wants to send me $$$ every month to tell everyone their stuff HAS to look like this.