Hi i have a 98 blazer lt 4.3 vortec 97k. i was wondering what is the safest coolant to put in my truck. i heard the orange stuff is bad for the gaskets and is not a good coolant for blazers. is this true? what coolant would you suggest?
thanks

 

yes that is true that the orange stuff is bad. flush your system out with water and then put the Preston green antifreeze but dilute it 60% distilled water and 40 green antifreeze........

 

so your saying once i flush out the coolant to put 60% water in and then 40% coolant in it? am i only suppose to flush out the radiator?
thanks david

 

If you are going to change to a different coolant you should fluah the radiator, heater core, & remove both block drains. If you only flush the radiator you still have more than 1/2 of the old coolant in the system.

People will argue till the cows come home about Dex Cool vs regular antifreeze. Dex Cool problems are generally associated with lack of maintenance. If your coolant is reasonably clean and you are having no problems I would flush & refill with Dex Cool if it were mine. I have a 1996 with 182,000 miles with Dex Cool and no problems. But it has been changed several times.

The normal recommended concentration is 50-50. It is a good idea to use distilled water instead of tap water. Also if you do use regular antifreeze read the jug. Some is pre mixed at 50-50 so don't use water with this.

 

ya my fluid i like a brown color. so i should flush the whole system?

 

I tried hard to run dex in my 03, I flushed it out and put dex back in about every other year, this year was the last, now I'm running green.

Remove your radiator cap and take a good look at it, does it look like someone dipped it in poo?
Clean out your over flow tank, I like to fill it to the top with water, then take the hose off of the radiator side that goes to the over flow and put it down, now take the hose out of the over flow and let it drain out.
Once it's drained, do you see a brown coating in the tank?
If you say yes to both of those you may want to do a full flush, and use the flush chems to remove some of the brown crud out before filling full of green.

I wish I swapped out to green @50k when I did my first flush...

And my blazer has a drain plug on the driver side of the engine, I jack that side up and I can get to it by the wheel well with a 15mm socket.

 

heres the thing with flushing..especially if you have dexcool in it now...if you plan on staying with it.., stay with it..if not, you have to completely remove all of it including the fluid in the overflow tank and the heater core if not, your asking for problems. They do not mix well(antifreeze/water and Dexcool) and cause severe corrosive action to gaskets and internal water passages..thats as far as im going with this lol

 

I agree if your coolant is brown that you should flush. Using a cooling system flush product would be best but you probably will never get all of the crud out. There are drain plugs on both sides of the block just above the oil pan. I use a 9/16 socket but use what ever fits the best. Use a 6-point socket to avoid rounding the head of the drain plug as they can be tight. Put a little pipe sealent on it as it is a pipe thread and it does not have to be gorilla tight. If you have 4wd you may not be able to get to the drivers side one so you will only drain one side of the block if you can't get it out.

Some causes of dex cool going bad are:
1. Allowing the coolant level to get low so air is in the system. This can be caused by a bad radiator cap as well as just not checking the fluid level. Even if your reservoir has coolant in it take the radiator cap off on occasion when the engine is cold. If the resrevoir is full and radiator is not full either the cap is bad or the hose to the reservoir is leaking.
2. Not checking the condition of the coolant and replacing it when needed.

 

I kept my coolant full, and I was sure I could get the dex to work!

I did an extended flush the other day, I did two 15min flushes before that when I decded I was done with the dex, I put green in after the two flushes and let it go for a week, then I checked my reserve tank to see how it looked, and I saw lots of floating brown crud, so I drained, flushed with water, and used a extended flush, I flushed it for 3 days straight while helping my sister in law move while hauling a trailer around, then I found out it was to get cold...
So I flushed the cleaner out and filled with green, when I pulled the cap off while the radiator was very hot and stood back, for about 2 seconds the water that came out was brown.

Before this I flushed I think it was last year or two years ago, I forget for sure, but I made sure I was always full on coolant, but recently I noticed that my over flow was looking more brown than orange...
I have no leaks, and I replaced my radiator cap last time I flushed...
I thought that I could make dex cool work, and I ignored others telling me to just get rid of it, now I have to worry about my intake gasket going out on me...

Dump the dex, the only down side is you need to change the green more often, but in my case, I think the green will last longer.

My wifes car has dex in it still, and I think it will stay with dex unless I start seeing the same problems I had.

And you need to make sure all of the dex is gone, best way to do it is to remove the thermostat and run the engine with water, drain and repeate with heater on.

 

I did this. I had Dexcrap in my 98 when I bought it. I promptly flushed it fully and put in green antifreeze. butafter a month I had a little brown gunk in the green fluid. It is very hard to get all the dexcool crap out. but after the second flush and refill it was good. I found the dexcool had gunked up so much that it had gunked up my water pump. The green stuff lasted long enough to get the old dexcool broken down and that's when i found out the water pump was bad. So when I replaced the water pump is when I replaced the green antifreeze. After that it was good.