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Doing Coolant Flush on 97

Woody35

Woody35

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Alright im going to do a coolant flush next week when i get time. anything i should know that is special to a diesel or 6.5. ive never done one on a diesel just gassers so i dont know. i know i have dual thermostats and im going to get the lower temperatures because i dont do a lot of highway driving. anything else i should be aware of?
 
If you really want to do a service good, remove the radiator all together, and clean it with cleaner / scrubbing bubbles.

And on re-fill, there is a bleeder on that thermostat housing you need to crack open while filling/running to let the air out.
 
If you have DexCool, stay with it because DexCool and Green don't mix too well, unless you can flush the DexCool thoroughly.

Make sure you use Distilled water w/DexCool.
 
Get rid of dexcool, green is more common and less finnicky. Put a garden hose in the bypass port and run about 20 gallons of water through the block, that should be good enough to put in long life green, it worked for me. The rad takes about 15 min. to remove, so I would suggest, as Matt did, to remove it and clean it thoroughly, be sure to stop up the trans cooler lines so you don't get water in them. I did mine this week, and boy was there junk in it. Should run cooler while towing now. Just my 2 cents, good luck.
 
whoever had the truck last looked like they did all the maintencance at the dealer so im assuming its still dex cool. plus it looks like he did a little off roading so i got a brand new driveshaft and transfer case out of the deal
 
Sweet. Just a thought here, when I flushed mine, I also flushed the heater core in reverse, so from the rad back to the therm. housing, and I got chunks of rubber to come out that had been blocking my heater core coolant flow. Couldn' hurt. FYI, the rubber was from the AC delco "million dollar" thermostats.
 
It should be good.

Another product that is good is called RMI-25. It is sold by the guy who owned GM Diesel forum.
 
I threw some watter wetter in there, I guess everyone's theary is,

'it can't hurt'

Its a baby step i'm sure, but every little bit helps for sure.
 
Think long and hard on that coolant switch...Like JMJ said, "They don't mix" and you'll end up with "Sludge"......On the flip side like Mfgguru said, and I agree, "The Dexcool is not as common and finnikey (sp)....If you do it, just be ready to flush the complete system.....Some people swear by Dexcool....Just passing along that sludge story because it aint a pretty site.
 
Or, you could use some of that green that 'mixes', that way if you don't get 100% no worries... nothing wrong with a 95/5 if its mixable.

I heard that if you get dexcool inside your engine block it can turn a simple head gasket into an engine, turns the oil to muck.... could be heresay. Either way, I'm glad that my A/F is the color it should be, green.
 
JMJNet said:
If you have DexCool, stay with it because DexCool and Green don't mix too well, unless you can flush the DexCool thoroughly.

Make sure you use Distilled water w/DexCool.
Click to expand...

Good point. 6 gallons of distilled water would be under 10 bux, so might as well used distilled, unless your buying the pre mixed 50/50. (but you end up paying 4 times as much for the distilled water), but easier/faster.
 
I've owned used vehicles, with the exception of one new one, all my life.

I change my coolant every two years, and have a chemical flush done every 4, by either one of two rad shops that have been in the business for a very long time.

I ask occasionally about dex-cool, they say that they can get it, but prefer the green with a two year change.

They have seen problems, of what sort I can't say.

They likely see more cooling systems in a week, than there are people on this forum, I'll stick with their advise.

Dex-cool is probably fine, but so is green.
 
chickenhunterbob said:
I've owned used vehicles, with the exception of one new one, all my life.

I change my coolant every two years, and have a chemical flush done every 4, by either one of two rad shops that have been in the business for a very long time.

I ask occasionally about dex-cool, they say that they can get it, but prefer the green with a two year change.

They have seen problems, of what sort I can't say.

They likely see more cooling systems in a week, than there are people on this forum, I'll stick with their advise.

Dex-cool is probably fine, but so is green.
Click to expand...

Yep, I agree. If the original dex-cool in there is good for100k+ miles, can't be too bad... Green leaks are easier to see too.
 
From what I have read, the reason for sludging is the mix between the two types or DC with regular water. I can see why it is easily mixed because when it just came out, it was probably not very easy to get. So people just bought the one that is available. Hence the bad name for DexCool.
 
Was probably a planned scam to get people to buy coolant from GM instead of aftermarket.

Another reason they are half belly-up.
 
Don't quote me on this but there is also something with the Dexcool and aluminum corrosion when air is introduced........I think?

Maybe someone else has heard this?
 

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