Having a problem with the coolant flush. When I open the radiator valve the only fluid that drains appears to be the contents of the overflow tank. What am I doing wrong? How is the flush done?

Are you opening the Overflow tank cap?

My radiator would drain along with the Overflow tank when i opened the pet-cock on the radiator.

I would close ,refill ,run at 2000+ RPMS, drain ,repeat,repeat.

Yes, but it doesnt seem to draw fluid from the overflow tank. I assume it doesnt matter if the engine is hot or not when doing the flush. Interestingly, I left the petcock open, after it stopped draining. Went into the house, when I returned more fluids was coming out - unknown how long this fluid was draining. I havent tried to add more water yet as I have to leave for a couple hours but I will try again when I return.

I did mine Hot so both T-stats were open ;)

So I should close the petcock, fill the overflow tank and close the cap and start the engine, keep it running until the engine is hot...then see if it draws fluid from the overflow tank? Sorry if I'm dense but I'm trying to figure out the mechanics of how the radiator fills from the overflow tank.

I can get about 2 gallons out when I drain the radiator during each flush...so I figure I'll drain what I can about 2 gallons on my last flush and add 2 gallons of antifreeze and call it good. I don't see how anyone gets 21 qts out furing a flush unless they are draining the block. I havent seen any description about how to purge air in any of the past threads. Anyone know how to do this?

Isn't that bolt on the thermostat housing used to purge/burp/bleed the air? Seems there was something on this in my 02 manual ~

Dmaxducker

If your still working on it ,yes drain the Rad,close Pet-cock and refill Thur the Plastic reservoir tank.
The system is closed and will by vacuum suck the fluid from the reservoir tank.

The truck must be hot and fluid must be circulating with open T-stats.


Good luck

Isn't that bolt on the thermostat housing used to purge/burp/bleed the air? Seems there was something on this in my 02 manual ~

Not necessary to bother with this bleeder. Just drain fill and raise rpm's to circulate fluid.The air will burp out on it's own.

I can get about 2 gallons out when I drain the radiator during each flush...so I figure I'll drain what I can about 2 gallons on my last flush and add 2 gallons of antifreeze and call it good. I don't see how anyone gets 21 qts out furing a flush unless they are draining the block. I havent seen any description about how to purge air in any of the past threads. Anyone know how to do this?
I got mine out............except for maybe a Quart..........

Dealer did a Block Heater R&R........it's all good now............

Seriously though, the coolant is supposed to be good for 5yrs/100K miles........mine with 50K on it looked nice and still had good color.....not brown or anything either.

It is a good idea to use distilled water in place of tap water when refilling.

T:cool: NY

The air is purged thru circulation.Drain Radiator and Reservoir refill repeat.In between raising RPM's to 2k or better and holding for a minute or two.

When I was done my fluid was near clear.I then drained off one more time and replenished with straight Antifreeze. Took nearly 3 gallons IIRC.

My coolant was heavily sooted.The above procedure worked like a charm for me,without a hiccup.

Heres how I would do it. First of all I never touch a radiator petcock unless I absolutely have to, eliminates any problem of it sealing again. Siphon what you can out of the reservoir. Then take the top rad hose off at the radiator where the spring clamp is. Slide a small hose down the side of the radiator tank and siphon it out. You should get out over 2 gallons. Put the hose back on. Take the gold/yellow bolt out of the top of the t-stat housing. Its the one on the top with a 12mm head. Pour coolant mixture in until coolant comes out of the bleed hole. When it starts to come out put the bolt back in, making sure not to lose the black washer that goes with it. Pour the rest of the coolant in and you're good. Try to measure what you take out and thats what you should be able to put right back in using this method, you will lose just a little on the floor.

<TABLE height=2551 cellSpacing=0 cellPadding=0 width=660 border=0 cool gridx="16" showgridx gridy="16" showgridy><TBODY><TR height=211><TD vAlign=top align=left width=654 colSpan=16 height=338 csheight="211" xpos="3" content>I have one of these so it makes it a little easier



</TD></TR><TR height=3><TD width=2 height=335 rowSpan=3></TD><TD vAlign=top align=left width=172 colSpan=11 height=335 rowSpan=3 xpos="5">http://www.mityvac.com/images/07201.jpg</TD><TD width=17 height=3></TD><TD width=447 colSpan=3 height=238 rowSpan=2></TD><TD width=1 height=3><SPACER type="block" width="1" height="3"></TD></TR><TR height=235><TD vAlign=top align=left width=17 height=235 xpos="177"></TD><TD width=1 height=235><SPACER type="block" width="1" height="235"></TD></TR><TR height=97><TD vAlign=top align=left width=464 colSpan=4 height=97 xpos="177">http://www.mityvac.com/images/7201.gif</TD><TD width=1 height=97><SPACER type="block" width="1" height="97"></TD></TR><TR height=199><TD vAlign=top align=left width=656 colSpan=18 height=328 csheight="199" xpos="0" content>The Fluid Evacuator Plus, a large 8.8 Liter (2.3 gallon) capacity bi-functional manual unit, can be used to extract and dispense a wide-range of fluid types including:


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sorry about the long post, not a cut/paste master yet.

Doing it your way you don't get a complete change out or flush. :o:

I drained, filled,repeat, mine till coolant was clear coming out of radiator and then added straight Long life tang. :D

I guess you could do it this way two or three times until it was clear. Just trying to give an example of another way to do it, not saying that my way is right or your way is wrong, just another way to do it.

I may be dating myself here... They don't put drain plugs on each side of the engine block anymore?

Here's yet another way.
1. Disconnect the top radiator hose from the radiator.
2. Remove the recovery tank cap and crack the old garden hose in there to keep it near full but not overflowing everywhere. Leave it running to maintain the recovery tank water level while flushing.
* Note: Flushing will start after the truck is hot and the T-Stats open which will allow fluid to start coming out of the removed radiator hose.
3. Let the engine run, relax and drink a cold one untill the fluid leaving the engine out of the removed hose is clear.
4. Shut off garden hose and engine.
5. Replace top hose of radiator and drain the petcock untill everything is empty.
6. Fill up with a good 50/50 to 60/40 mix of Dex and Distilled water. Refer to cooling system capacity in the owners manual. Be sure to add the amt of Dex needed first to be sure you have the correct amt in there then top off with Distilled water afterwards.
7. Run the RPM's up a couple times per Mac's instructions to help purge air. Recheck the recovery tank level and add fluid as needed.

* You may have to add a little more fluid to the recovery tank after a day or so after any residual air has worked out.

Thanks, I think the key to my problem was not starting the flush with the engine hot... as I have learned now....allowing the thermostats to open clearing the flow of fluid... finished the flush using distilled water then added 11 qts of DexCool. Drove it and finished adding distilled water until the transfer tank remained full.

I saw some of you add back in straight Antifreeze... Isnt this bad, doesnt it eventually eat up the Radiator? Shouldnt there always be a dillution of distilled h2o?

I saw some of you add back in straight Antifreeze... Isnt this bad, doesnt it eventually eat up the Radiator? Shouldnt there always be a dillution of distilled h2o?


The way it's figured doing the flush is my system was near emptied of coolant and was filled with distilled water. I drained off half if not more than half the distilled water and added straight coolant.I believe the capacity is 21 quarts ,someone correct me if I'm wrong it's early.

Half would be 2.5 gallons of coolant,I replaced with just about 3 gallons of tang.
It's mixed by flow, that's for sure.

Here's yet another way.
1. Disconnect the top radiator hose from the radiator.
2. Remove the recovery tank cap and crack the old garden hose in there to keep it near full but not overflowing everywhere. Leave it running to maintain the recovery tank water level while flushing.
* Note: Flushing will start after the truck is hot and the T-Stats open which will allow fluid to start coming out of the removed radiator hose.
3. Let the engine run, relax and drink a cold one untill the fluid leaving the engine out of the removed hose is clear.
4. Shut off garden hose and engine.
5. Replace top hose of radiator and drain the petcock untill everything is empty.
6. Fill up with a good 50/50 to 60/40 mix of Dex and Distilled water. Refer to cooling system capacity in the owners manual. Be sure to add the amt of Dex needed first to be sure you have the correct amt in there then top off with Distilled water afterwards.
7. Run the RPM's up a couple times per Mac's instructions to help purge air. Recheck the recovery tank level and add fluid as needed.

* You may have to add a little more fluid to the recovery tank after a day or so after any residual air has worked out.Just wanted to mention that if at all possible substitute the tap water (garden hose) method above with distilled water during the flush. Just pour it out of the jug into the recovery tank keeping it full while flushing. The reason I stated above to use the garden hose was because many people don't use the distilled water. Distilled water is way better for the system and the route I take. It will take a few more jugs to do the flush but at less than $1 a gallon it's well worth it to keep the scale forming minerals out of the system. Your radiator will in turn look like new years down the road. :)

To elaborate on what Mac said the reason to add pure Dex at the end of the flush is to simply assure you get enough in there (approx 11 -12 qts) to get the 50/50 or 60/40 mix as all the water can't be drained after the flush. And yes it will mix itself afterwards.

dex cool turns into an acid if you don't change it sooner then 5 yrs we have termendous problous with the v6 and intake manifolds leakin cuz of the dexcool eating the gasket. I'm gonna do a full flush and use the new coolant that can work in any system. in other words the urhin antifreeze

dex cool turns into an acid if you don't change it sooner then 5 yrs we have termendous problous with the v6 and intake manifolds leakin cuz of the dexcool eating the gasket. I'm gonna do a full flush and use the new coolant that can work in any system. in other words the urhin antifreeze
DexCool had better be acidic to begin with as it uses 2 organic acids to inhibit corrosion. A good read that should reduce the amount of mis-information is http://www.motor.com/MAGAZINE/Pdf/082004_04.pdf