98 Chev Blazer Radiator Flush

[PAkev]

I planned to flush my radiator this weekend. Earlier in the week, I purchased a bottle of radiator flush/cleaner and then topped the radiator off with water and drove for about 200mi.

The guy at the auto parts store conveyed the radiator holds 1.5 to 2 gal of antifreeze so I agreed to purchase 2 gal. However, when opened the petcock valve, I was only able to get about 1/2 gal out. I presume the rest of the fluid is in the block, water pump, etc.

How do I get the old water and anti freeze out so that I can replace with the fresh antifreeze?

Helpful thoughts appreciated.

 

[Bob_VT]

Re: 98 Chev Blazer Radiator Flush

Remove your lower radiator hose and you might have to remove the thermostat housing ....

It's not a bad idea to replace the thermostat anyway.

You need to release the air lock to allow the block to drain.

Be sure when you re-fill the system you bleed the air out too.

 

[Coors]

Re: 98 Chev Blazer Radiator Flush

And you have 2 block drains, one on each side, just above the oilpan.

 

[puddle jumper]

Re: 98 Chev Blazer Radiator Flush

Just be careful of what kind of antifreeze you use or flush the system extremely well. The stock Chev antifreeze does not mix with the generic stuff. What happens is the two antifreeze turn to what looks like mud and plugs up your rad, heater core and your engine passages.

 

[PAkev]

Re: 98 Chev Blazer Radiator Flush

Thanks for the info.

The GM antifreeze I have is what is called "DEX COOL" and is orange looking rather than the aqua green color of conventional anti freeze.

BTW, if I can't get the air block out, is there any harm filling the radiator back up and driving the car around for a day or two to get the block out.

 

[Coors]

Re: 98 Chev Blazer Radiator Flush

Dex Cool is a killer- flush it all out.

 

[Bob_VT]

Re: 98 Chev Blazer Radiator Flush

If you are going to flush the system..... re-fill it with good old green anti-freeze. No gimmicks and a far better reputation.

If you want to drive it to get the air pockets out I would not do it. If you end up with an air pocket it can disrupt the coolant and cause a hot spot.... which will lead to learning far more about an engine than you planned. You could burn it up.

Return the dex cool to the parts store and GO GREEN

 

[Navy Jr.]

Re: 98 Chev Blazer Radiator Flush

I agree with the others that Dex-Cool can be "Death-Cool," but it sounds like the poster already bought the stuff and is ready to use it.

Dex-Cool is okay if you stay on top of it. GM says it is good for 5 years or 150,000 miles, whichever comes first. Unfortunately, a lot of owners figured that meant they never needed to even look at it for 5 years or 150,000 miles.

One problem of neglect is that if the fluid level runs low and the overflow reservoir runs dry, air gets into the system. Air and Dex-Cool are not a good chemical combination. That's when mud and sludge start to form, gaskets start to melt, fluid starts to leak on the deck, and engines start to overheat.

So, it's okay to use Dex-Cool; just check it every month like you would your oil level. Don't let it run low. And its best not to wait 5 years or 150,000 miles to flush it out. Three years is really better.

Having said all of that, the truth is that I converted my Buick Regal to the green stuff in its fourth year and never looked back. But my sons have GM cars with Dex-Cool and haven't had any problems (cause DAD SAID TO KEEP ON TOP OF THE STUFF!!).

 

[Coors]

Re: 98 Chev Blazer Radiator Flush

It ain't worth the $15 throw it out, compared to the bill that you will get for repairs.
search for Gary's thread.

 

[PAkev]

Re: 98 Chev Blazer Radiator Flush

Thanks for the heads up on the DEX COOL. I'll try to return it for another brand. From the context of other posts, I presume it is OK to use the conventional Anti Freeze such as Prestone as long as I flush the loop thouroughly.

In order to do this, I will have to run it on "Water Only" for a while to dilute the remaining dex cool after draining. We are still seing evening temps below freezing so perhaps I better wait a month or two to do the fluid conversion.

 

[Coors]

Re: 98 Chev Blazer Radiator Flush

Once you get it warmed up, you can start cracking plugs, with it running, and a slow hose feeding it.
the therm will open and close constantly, but in one hour, it will be flushed.

 

[JCF350]

Re: 98 Chev Blazer Radiator Flush

http://forums.iboats.com/showthread.php?t=234754

 

[PAkev]

Re: 98 Chev Blazer Radiator Flush

Thanks for all the helpful info.

I returned the Dex Cool for regular anti freeze and also purchased a flush kit adapter that hooks a garden hose to the heater hose to wash water through the block.

Shes now running like a top.