Drain & fill cooling system
Thread Starter
Burning Brakes
Joined: Nov 2001
Posts: 1,162
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From: Bel Air MD
Drain & fill cooling system
Does anyone know approximately how much fluid comes out when you open the radiator drain **** and let it drain? I may drain & fill this weekend and I am trying to get an idea of how much coolant to buy in order to acieve a 50/50 mix.
Le Mans Master
Joined: Sep 2003
Posts: 8,847
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From: Longview Texas
Originally Posted by rwlc5
Does anyone know approximately how much fluid comes out when you open the radiator drain **** and let it drain? I may drain & fill this weekend and I am trying to get an idea of how much coolant to buy in order to acieve a 50/50 mix.
You need a gallon of Dexcool and a gallon of distilled water, plus a little more.
If you leave the cap on the overflow tank on when you open the drain valve on the radiator, it will siphon all the coolant out of the overflow tank along with what is in the radiator.
Safety Car
Joined: Jul 2004
Posts: 4,806
Likes: 70
From: Rochester MN
Yes the tank will go down as soon as you start the engine after refilling.
Then slowly keep adding to bring it up to the full mark.
You will get out 8 quarts. I used one gallon each of antifreeze and distilled and did not need any more. So buy one of each to start.
Then slowly keep adding to bring it up to the full mark.
You will get out 8 quarts. I used one gallon each of antifreeze and distilled and did not need any more. So buy one of each to start.
Tech Contributor
Joined: Oct 1999
Posts: 41,058
Likes: 9,820
From: Charlotte, NC (formerly Endicott, NY)
I follow the Service Manual instructions but add an extra step. Once the radiator is drained I refill with clean drinking water (as recommended in the Service Manual) and run the engine until it gets hot enough to open the thermostat. After letting the coolant circulate for a few minutes I shut the car off and drain the radiator again. I do this two times and it gets most of the old coolant out of the rest of the cooling system. Then I refill half the cooling system capacity with DexCool and the rest with water. If you do not get most of the Dexcool out of the system before putting in new coolant you will have too high of a percentage of antifreeze to water which reduces the heat transfer capability of the cooling system. I have never used distilled water in any of my cars and have not had any problems. I don't even know whether the plant uses distilled water on initial engine fill. It all depends on the quality of their local water supply.
Bill
Bill
Le Mans Master
Joined: Sep 2003
Posts: 8,847
Likes: 795
From: Longview Texas
Originally Posted by rwlc5
The drain & fill procedure says to remove the overflow tank cap and then open the drain. Are you saying that if you remove the cap that the overflow tank will not drain?
Once the tank is empty, I then remove the cap so the rest of the system will drain faster.
Try it with the cap off and see what happens. The instructions in my chassis service manual says to leave the cap on.
