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Old May 20, 2016, 02:12 PM
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Flushing the LS1 Coolant

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Old Apr 4, 2002 | 05:57 PM
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Default Flushing the LS1 Coolant

Hey all...I wanted to ask a few questions about flushing the coolant from my LS1. I heard that it should be flushed at least 3 yrs/50K miles, despite GM's claims that it lasts till 5/150K. I'm already starting to see that brown crud on the resevoir dipstick and I wanted to do it sometime soon, but I had some questions before I do it:

-Once you flush the system, you have 100% water in the block. Do you have to drain the block by pulling the block coolant plugs before adding 50/50 Dex-Cool/Water? Or can you just mix in enough Dex-Cool to balance out the water in the block and then add 50/50 from there? If so, how much water is left in the block after fully flushing and draining the radiator?

-How do you make sure the system is completely bled? Do you just leave the radiator cap open and keep adding until it doesn't go down anymore? Are there bleeder plugs you should use?

-Also, the procedure calls for "distilled" water, and someone told me I can get "distilled" water at the supermarket. Is this the same as spring water? How much will I need to get the job done?

Thanks for the info
Mark
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Old Apr 5, 2002 | 09:09 AM
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From: Schiller Park, ILL Member: #317
Default Re: Flushing the LS1 Coolant

Here is a tip. I drain and refill just what coolant is in my radiator every six months. That way the new is always mixing with old, keeping the system fresh. This saves a lot of time and is a lot easier, IMO. I never get any build up of any crud using this method. My coolant is always fresh and clean, and the system works great. I have been doing this in various cars of mine for years.

You can buy distilled water at the supermarket, but it will be called “distilled water”. Spring water is not distilled. Spring water still has minerals in it, distilled water means there are no mineral deposits in it at all. It is used for steam when ironing cloths and such because it will leave no deposits. You can also buy distilled water at auto parts stores. It may also be called “battery water”.
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Old Apr 5, 2002 | 10:12 AM
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Default Re: Flushing the LS1 Coolant

I was thinking about doing that...just draining the radiator. But I figure I may as well flush it once, cuz I got it used and who knows what the previous owner did. <img border="0" alt="[Pontiac]" title="" src="graemlins/formula.gif" />

I may just do that anyway, flush the radiator and clean the crud out of the resevoir tank. It's only got 25,000 miles on it, I haven't had any cooling problems so maybe draining the rad and cleaning out the recovery resevoir will be enough until 50K. That'll get some of the crud out of there at least. Besides, they say as long as the system's air-free, it won't generate that crud...that's why it collects in the resevoir tank mostly.

How expensive is distilled water? Do you HAVE to use it?

And do you have any idea on the bleeding procedure?

Thanks
Mark
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Old Apr 5, 2002 | 10:21 AM
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From: Schiller Park, ILL Member: #317
Default Re: Flushing the LS1 Coolant

Distilled water is no that expensive. Maybe $2.50 for a gallon at most. I always use it, but you don’t have to use it. Any clean drinkable water will do, but I just like the idea of the mineral free distilled water myself for the extra couple of bucks.

To bleed the air, I just fill the radiator and let the car run with the radiator cap off till the T-stat opens, then fill it again and cap it off. Drive it around for a while and then check the overflow. If it’s low, fill it up. I think there is a bleeding “procedure” you can do, but I never have, and it’s been just fine. This is again the same procedure I’ve followed in my current LS1 for two years and in all my other cars for many years...
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Old Apr 5, 2002 | 10:24 AM
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From: Schiller Park, ILL Member: #317
Default Re: Flushing the LS1 Coolant

Oh, and it probably would be a good idea to just flush the whole thing this time and then get into the habit of just draining and refilling the radiator every six months to a year.
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Old Apr 6, 2002 | 12:19 AM
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Default Re: Flushing the LS1 Coolant

you definately need to used distilled water, especially with aluminum heads and block. it really help keep corrosion down.
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Old Apr 6, 2002 | 09:39 AM
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Default Re: Flushing the LS1 Coolant

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by RPM WS6:
<strong>Here is a tip.....

You can also buy distilled water at auto parts stores. It may also be called “battery water”.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">just make sure it say's 'battery water' and not battery acid. LOL
<img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />
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Old Apr 6, 2002 | 11:59 AM
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Default Re: Flushing the LS1 Coolant

does anyone have a link ot the method for flushing the coolant?
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Old Sep 4, 2002 | 08:33 PM
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Default Re: Flushing the LS1 Coolant

ttt
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Old Sep 4, 2002 | 09:04 PM
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Default Re: Flushing the LS1 Coolant

Most of where that brown crud is from is mixing normal antifreeze with dexcool. The easiest way to flush it is get some cleaner stuff at a car store and use that. Just open the little vavle on the bottom of the radiator and watch it drain out, you can put a hose in the top and start the engine to get the rest of the antifreeze out, from there follow the directions.
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Old Oct 11, 2007 | 01:45 PM
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That will not flush what is in the block. The thermostat will not open with cold water constantly pouring in. If you are mechanically inclined, Do the following.

Step 1. Buy a 160 thermostat.
Step 2. Removed the old T stat and put NO thermostat in.
Step 3. Drain the coolant, start the car, and run a hose on the top.
Step 4. Stop the water, and keep the car running for a SHORT time to get all the regular water out of the block.
Step 5. Put the 160 stat in OR whatever new thermostat you buy.
Step 6. Fill the water with nothing but distilled water and 1 bottle of water wetter or some kind of additive.
Step 7. Start the car and complete the bleeding process, when the T-stat opens the radiator will empty into the block, you will probably have to shut off/on the car a few times to make sure you dont overheat it.
Step 8. in 10/20k miles remove radiator fluid and fill up with distilled water and water wetter.

Tim
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Old Oct 11, 2007 | 01:59 PM
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Wow I dug up an old thread. Searching sucks
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Old Oct 11, 2007 | 02:08 PM
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lol it was only 5 years
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Old Oct 11, 2007 | 08:09 PM
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There's a block drain on the drivers side by the alternator. If I remember right it takes a big hex wrench. If the coolant comes out clear and clean you really don't need to flush the system. If you look just below the radiator cap you will see a small hose going to the engine. This will bleed the block so all you need to do is continue to fill the radiator until it won't take any more coolant. It takes a while for the air to bubble out. You can buy a plastic funnel with an attachment to fit on the radiator which makes fiiling a lot easier and cleaner.
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Old Oct 12, 2007 | 08:02 AM
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i have always used the prestone that is premixed
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