How much coolant needed for refill/replace

Buick Ownership
2004 Lesabre
Wanting to do a coolant flush/refill/replace on my 2004 Buick LeSabre. 170k. Replaced leaking intake manifold gasket earlier this summer.

How much coolant to buy to refill? Two containers?

Do you use a flush chemical or just water (distilled? Or garden hose)?

Do you absolutely need to jack up front end?

Any tips appreciated!



Full Member
Staff member
Buick Ownership
Regal GS 2017
Page 5-99 of the owners manual states capacity is 10 quarts. So you need a liitle over a gallon of antifreeze concentrate and a little over a gallon of distilled water.
You are the judge as to whether it needs a chemical flush.


Top Dog
Let me ask a couple of questions. When the intake manifold was worked on, was the cooling system refilled with 50/50 or 60/40 mixture of DexCool? Or was it refilled with water or another green coolant not compatible with DexCool?

If the system was filled with 50/50 to bring it back up, I'd just open the coolant drain on the bottom of the radiator , drain what comes out, and refill with 1/2 full strength DexCool OR Prestone Mixes With Any Coolant (same thing ) and 1/2 distilled water from Kroger or Walmart...

If the system had another noncompatible coolant put in, I'd take off the upper radiator hose and then use garden hose to run water into the thermostat housing through engine and then through radiator till it comes out clear.

Then I'd put everything back. Add 5 quarts of pure Dexcool through the radiator cap. IIRC it may not take it all at first. But that will mix with the 5 quarts of water that stays in the engine and radiator IIRC to give you a 50/50 mixture. Then after running and letting the air burp out of the system at the bleed screw and from the heater using the run at 2000 for 15 seconds and then idle a while, repeat 4 times, to get the air out of heater --all done after engine is fully up to temp, you can fill the reservoir to the level with either pure DexCool or 50/50.

You may want closer to 60/40 to get lower freezing temp if you're in a colder part of US.
Check the table on the bottle of DexCool or Prestone Mixes any coolant.

Recheck coolant level frequently to be sure all air is out.


New member
Buick Ownership
Lesabre 2000
Hi, You would be needing 10 qtz or 9.5liters.
You can use distilled water to flush it. Do not use tap water. Run your engine about 10-15 mins or until the fan turns on. Let the engine cool down before opening the plug again. Safety first.
It is best to jack up front end for more clearance when draining.
You can also buy a pre-mixed coolant.


Active member
Buick Ownership
2003 lesabre limited
So if you use just the petcock under the radiator to drain fluid, you won't get all the fluid out every time you drain it. For a proper flush you'll have to run distilled water 2-3 times through the system and then drain it. I know there are also drain plugs on the engine block somewhere under it but I'm not sure where they are exactly located but theoretically if you open those you can drain all the fluid and flush it better

What I did:
Drain as much coolant comes as comes out
- add distilled water and coolant flush
- drive car around while monitoring engine temp and get it up to operating temp (10-15 mins of driving)
- get back home let it sit a little
- drain everything
- refill with distilled water, drive again, drain again
- refill with distilled water, drive again, drain again ( hopefully by this time what you're draining is gonna be somewhat clear looking)
- refill with 50/50 coolant water mix and run the car while burping the system to purge air out.
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