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Flushing cooling system

FROM RADIATORS TO THERMOSTATS TO HEATER CORES, IT GOES HERE.

astroturf
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Re: Flushing cooling system

Post by astroturf »

I don't think so.

I just routed mine around the front heater core hoses to give me that windshield cracking heated fluid in the winter.

It works pretty good too.

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Re: Flushing cooling system

Post by MountainManJoe »

That's a good idea.

My nozzles get jammed up in the winter.
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Re: Flushing cooling system

Post by MountainManJoe »

OK I finished the job last night, and came up with a very quick and easy way to flush out the entire cooling system, including rear heater! No cutting lines, no special adapters, and you only need to disconnect one hose. It goes something like this:
  • I took out the intake and washer fluid/coolant reservoir just to have room to work.
  • Disconnect the the main heater return hose (it's the smaller diameter one of the two) from the valve assembly, and plug it. I stuck a cork in it, and put a hose clamp over it. I'm sure folding it over and putting a vice-grip on it will work just as well.
  • Start the engine, and turn on your rear heat
  • Continuously supply fresh water into radiator neck, until the water coming out of the valve assembly runs clear.
  • Unplug the heater hose, and turn off the rear heat. Repeat step #4
  • Now stop filling the radiator and wait until water stops flowing. Turn off engine.
  • Replace heat hose. Pour two jugs of coolant into radiator. It should just fit. Done!
One job down, about 6 more to go.

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Re: Flushing cooling system

Post by kkamakasi »

timelessbeing wrote:OK I finished the job last night, and came up with a very quick and easy way to flush out the entire cooling system, including rear heater! No cutting lines, no special adapters, and you only need to disconnect one hose. It goes something like this:
  • I took out the intake and washer fluid/coolant reservoir just to have room to work.
  • Disconnect the the main heater return hose (it's the smaller diameter one of the two) from the valve assembly, and plug it. I stuck a cork in it, and put a hose clamp over it. I'm sure folding it over and putting a vice-grip on it will work just as well.
  • Start the engine, and turn on your rear heat
  • Continuously supply fresh water into radiator neck, until the water coming out of the valve assembly runs clear.
  • Unplug the heater hose, and turn off the rear heat. Repeat step #4
  • Now stop filling the radiator and wait until water stops flowing. Turn off engine.
  • Replace heat hose. Pour two jugs of coolant into radiator. It should just fit. Done!
One job down, about 6 more to go.
This may be a dumb question but Astro Cargo doesn't have a rear heater right? Since it's a cargo?
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Re: Flushing cooling system

Post by MountainManJoe »

I don't know, but one quick look behind the driver seat will tell you right away.

I believe C36 is the RPO code for auxiliary heater.

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Re: Flushing cooling system

Post by kkamakasi »

timelessbeing wrote:I don't know, but one quick look behind the driver seat will tell you right away.

I believe C36 is the RPO code for auxiliary heater.
what's behind the driver seat?
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Re: Flushing cooling system

Post by snapple »

kkamakasi wrote:
timelessbeing wrote:I don't know, but one quick look behind the driver seat will tell you right away.

I believe C36 is the RPO code for auxiliary heater.
what's behind the driver seat?
There will be a heat vent there. Also you would have a separate heat controller on your dash for the rear ,if you have a rear heater. At least that is how my '94 is.
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Re: Flushing cooling system

Post by kkamakasi »

snapple wrote:
kkamakasi wrote:
timelessbeing wrote:I don't know, but one quick look behind the driver seat will tell you right away.

I believe C36 is the RPO code for auxiliary heater.
what's behind the driver seat?
There will be a heat vent there. Also you would have a separate heat controller on your dash for the rear ,if you have a rear heater. At least that is how my '94 is.
I only see one set of temperature controls in my astro cargo. I guess that means I dont have a second heater. Less work for me I guess when I flush the system. Thanks!

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Re: Flushing cooling system

Post by photo_van »

I just flushed my system today using the Timeless One's method; this is by far the best method I have seen anywhere. No cutting the heater hose for a tee (and getting the Squid all wiggly) and no crawling under trying to get that dang lower hose off and having it pour all over everywhere. The only thing I'd add is that a garden hose fits perfectly over the heater core tube, no clamp necessary, and you just run that into a bucket. Very clean. Also, I refilled with water, ran it hot, then repeated. Kudos to Timeless =D>

This method really should be stickyed. It didn't seem like I was going to be able to get 2 gal of AF back in there, so I blew back on the heater return hose a few times which flushed additional water out of the radiator fill neck. Lastly, it took running the engine hot (to remove air) before I could get close to 2 gallons of antifreeze in.
timelessbeing wrote: [*]I took out the intake and washer fluid/coolant reservoir just to have room to work.
[*]Disconnect the the main heater return hose (it's the smaller diameter one of the two) from the valve assembly, and plug it. I stuck a cork in it, and put a hose clamp over it. I'm sure folding it over and putting a vice-grip on it will work just as well.
[*]Start the engine, and turn on your rear heat
[*]Continuously supply fresh water into radiator neck, until the water coming out of the valve assembly runs clear.
[*]Unplug the heater hose, and turn off the rear heat. Repeat step #4
[*]Now stop filling the radiator and wait until water stops flowing. Turn off engine.
[*]Replace heat hose. Pour two jugs of coolant into radiator. It should just fit. Done![/list]
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Re: Flushing cooling system

Post by MountainManJoe »

If you liked this, you may also like my tranny flush procedure...
viewtopic.php?f=57&t=6356&p=66780#p66780

Let me know if the images don't show up for you.
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Re: Flushing cooling system

Post by gotmud »

I think Timeless has some great instructions there. My only question after reading everyone's posts on this topic...why doesn't anyone drain the block? Without draining it, you'll still have regular tap water in the system when you get ready to put the anitifreeze and distilled water in.
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Re: Flushing cooling system

Post by MountainManJoe »

Over time, the antifreeze will mix with the water to reach your desired proportion. If you don't do this in the winter, you don't have to worry about anything freezing. I have always used tap water without issue.

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Re: Flushing cooling system

Post by Cobra »

i think gotmud isn't so worried about the mixture as the chemicals in the tap water that can promote corrosion and other side effects inside the engine that's why the distilled water is important. I can only think of not too concerned about it or just plain lazy to be honest i don't even know how to drain a 4.3 :peep:
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Re: Flushing cooling system

Post by brokenwrench »

Cobra wrote:i think gotmud isn't so worried about the mixture as the chemicals in the tap water that can promote corrosion and other side effects inside the engine that's why the distilled water is important. I can only think of not too concerned about it or just plain lazy to be honest i don't even know how to drain a 4.3 :peep:

do you drink that corrosive tap water?,

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Re: Flushing cooling system

Post by Cobra »

the water at work is bad enough to upset your stomach my water is filtered :D
don't underestimate what is in the cities tap water
1998 GMC Safari AWD, BFGoodrich AllTerrain T/A
Jet performance tuner 91 octane preset, Jet under-drive pulleys
Rancho 999000 series shock, on-board controller to be installed later
DHC rock rails and skid plate Add-A-Leaf
G3500 front calipers
Zexel Torsen Diff
11" drums
180 amp Alternator
Long tru-cool 4590 trans cooler

1997 in storage (project coming soon)
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