Coolant flushed...and something else too...HELP

[rundmc]

Hey all,

Yesterday I flushed my cooling system for a coolant change. I went by the book (the Swingle Method) for flushing the system with a cold engine, low pressure water flush, etc. Made a lake in my garage that I'm cleaning up responsibly - nothing went into the storm drain.

After multiple flushes at both points, all of the green coolant disappeared as I was told to expect. The initial coolant that came out of the petcock on the radiator was very green looking, then the rest that was flushed looked very green. I kept flushing until everything looked clear.

This morning I started the install process on Toby's air bleeder kit. Front done first, no problem. Went to start the engine bleeder install and decided to shine a light into the empty reservoir bottle. At the bottom of the stainless bottle was brown sediment that I am assuming is rust. As a precaution, I removed the bottle entirely and flushed it out independently from the car. Now it is clean as a whistle.

My question is - If that was rust, what precautions do I need to take or what extra checks do I need to make before I put new coolant in and finish the process??? Am I sunk?

There was no evidence of rust IN the coolant when it first drained. It looked quite green. However, when I funneled it into appropriate jugs to take to recycling, the first bottle of coolant went into the funnel and took on a very dark color.

I have visions of the interior of my engine corroding horribly right now...

[SamHill]

Rust deposits in radiator. I would lose 0 minutes of sleep.

[rundmc]

Thanks. Much appreciated.

[David T]

You can never totally get the insides of the cooling system clean, even with chemicals. If the coolant comes out green (not dark brown and foul smelling) your system is pretty clean. You clean it up as best you can (you already did the bottle) and refill. If you are really anal, fill with water and repeat the flush as many times as your compulsive nature requires. Pressure test and then fill with 50/50 anti-freeze and soft water. The coolant in the header tank gets to slow down and is not very turbulent allowing any sediment suspended in the coolant to settle out. Kind of a natural trap.
David Teitelbaum

[stevedmc]

This is another good reason to not use so called lifetime coolant. My guess is the previous owner never did change the coolant. If you change the coolant every couple of years like you should, the rust will eventually be gone (unless it is really bad and you need a new radiator).

I would just change the coolant every two years and not worry about it, as long as you don't have any leaks.

[David T]

I don't care how often or what kind of magic fluid you use as coolant. You will always see some kind of sludge build up somewhere. Not in pipes or passageways, mostly where the size of the chamber gets large, such as in the header tank or the radiator. Completely normal and will not affect the operation of the cooling system until it discolors the coolant. At that point there is so much junk suspended in the coolant that it changes color and is WAY past needing to be flushed out. I prefer the green stuff. Still relatively inexpensive so you can change it frequently. I test the stuff every other year for strength and PH. After 5 years it gets flushed out and replaced. Be warned most of the newer exotic stuff does not mix well with the older stuff. Very difficult to flush the system well enough to change over. It takes disassembly to get all of the old stuff out. Like the over-priced brake fluid and syn motor oil, the older type, regular stuff is just fine in a Delorean that is used for occasional street driving. Find other things to spend your money on, like fixing up the cosmetics. Lifetime coolant is good till the next attendant tops you off with something else or works on the car and dumps it! All too often a K & N air filter is thrown out and replaced because the shop didn't know it was cleanable!
David Teitelbaum

[rundmc]

Thanks for the advice everyone. Best I could tell, the exiting coolant was still very green in the catch pans, although once it was poured into a bottle it looked dark and gross, but I assume that's because it was concentrated in a small container or some such.

Either way, I flushed like a crazy person more than a few times in both main hose paths. Then cleaned the bottle off the car. Put in a 50/50 mix of distilled water and Peak Long Life green coolant.

Had a minor issue with a leak during the initial pressure test, but a tighten down of a hose clamp solved that. Toby's bleeder kit really simplified the burping process. I was glad I took the time to install it today. I lost a little more coolant than I would have liked while trying to quickly fit the upper radiator hose back into the water pump, so I had to guesstimate the top-off amount of coolant after that. That stupid hose doesn't like to go back on in a hurry...

[Nicholas R]

This is why we do coolant flushes; to occasionally clean out those rust deposits :D

[Ron]

This is why we do coolant flushes; to occasionally clean out those rust deposits :D
+1
And every once in a while it is good to use a quality additive to flush it with. If you've never used one, you will be amazed at the rust and crud that comes out of a system you thought was clean, even if had frequent changes and top quality coolant in it all its life!

[Farrar]

This may be a dumb question, but my first car had been outfitted by a previous owner with a sort of T-fitting which allowed one to hook up a garden hose to it and flush the system that way. I have since seen such kits available. Are those recommended, or anti-recommended, for our cars? Why or why not? I ask because although I don't have a garage, I do have access to a garden hose. :)

Thanks,
Farrar

[David T]

Prestone sold an adapter kit with a yellow plastic fitting you cut into a hose to hook a garden hose to for flushing. Not a good idea on a couple of accounts. First off you can overpressurize the cooling system blowing up the radiator, heater core or bursting hoses. The other problem with it is when the plastic ages it can crack and burst losing all of your coolant. Best advice would be to replace the cut hoses and remove it. This advice is not Delorean specific, it applies to any car.
David Teitelbaum

[Farrar]

Thanks, David. Although I doubt it's possible to explode the system since it would be open for flushing, I think you're right about the cheap plastic. It did look pretty cheap to me.

Farrar