Mechanics

HOW MUCH COOLANT DO YOU PUT BACK IN AFTER FLUSH?

1998 GMC Jimmy • 6 cylinder Automatic • 125,708 miles

I will be doing a coolant flush. My vehicle takes 3 gallons. Do I put back in 3 gallons of coolant plus water in total? Or 3 gallons of coolant than add water back up to reservoir?
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Roycar71
June 15, 2012.




Not all liquid will drain out of block so system won't take 12qts and that is a 50/50 mix. So usually add antifreeze till full and what is in block dilutes to @50/50 mix. After test to see if protected to -25deg
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Docfixit
Jun 15, 2012.
I have a flush tee on my heater inlet hose. I will be doing a backflush than drain out remaining fluids from radiator. Does this method apply?

Tiny
Roycar71
Jun 15, 2012.
Yes there will still be water in block

Docfixit
Jun 15, 2012.
Can blow air through inlet hose to push water out?

Tiny
Roycar71
Jun 15, 2012.
Pull bottom radiator hose that will drain most

Docfixit
Jun 15, 2012.
Thanks.

Tiny
Roycar71
Jun 15, 2012.
How did it go?

Docfixit
Jun 16, 2012.
I had to do 2 vehicles. A GMC Jimmy and Ford expedition. I could not remove drain plug from GMC jimmy so I removed lower radiator hose but ford was easy to remove. After draining, I previously had a prestone backflush kit installed on both vehicle heater inlet lines and used a garden hose flushed water through them until I saw clear water. Then drained radiator again. Then I add some prestone "flush" and added water back up to reservoir full line and ran engine for 15 minutes. I flush again and added just water ran engine for another 15 minutes. Lastly, I flushed and added just about 1.5 gallons for gmc jimmy and 2.5 gallons for Ford expedition coolant. I let engines run for about 30 minutes with cap off reservoir to let system bleed out air and add just coolant. As you said earlier, it would not take full capacity because of diluted water in block. Both vehicles run good sofar. Thanks.

Tiny
Roycar71
Jun 17, 2012.
Good job that is how it is done bleeding out air VERY important

Docfixit
Jun 17, 2012.

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