Coolant Percentage Check

[timtom]

I have a 2004 Sierra 1500 with the 4.8 motor. I just replaced the engine coolant. Drain, flush, new thermostat and hoses, refill. What is the trick to get an accurate read on the coolant/water ratio. The question in my mind is: Do you get any circulation and mixing in the fill/overflow tank. Stated another way: If you put 100% coolant only in the fill/overflow would it quickly mix with the rest of the system coolant. Or will it sit there undeluted in the tank for a long time. If the later is true then where would you collect a sample to test for proper 50/50 ratio?

[redvett]

Have you looked at the coolant tank hosed and there routing? The coolant goes through the tank as the engine runs. Just wait a couple of days after driving and check it.

[Mr. Smith]

I have a 2004 Sierra 1500 with the 4.8 motor. I just replaced the engine coolant. Drain, flush, new thermostat and hoses, refill. What is the trick to get an accurate read on the coolant/water ratio. The question in my mind is: Do you get any circulation and mixing in the fill/overflow tank. Stated another way: If you put 100% coolant only in the fill/overflow would it quickly mix with the rest of the system coolant. Or will it sit there undeluted in the tank for a long time. If the later is true then where would you collect a sample to test for proper 50/50 ratio?

 

 

A refractometer is what you would use. a sample should be pulled out of the system and not the overflow bottle.

[Nytemare]

I would personally...and I always do....mix my coolant outside the vehicle. I take 2 bottles of 100% coolant and 2 empty bottles, half fill the two empties with coolant than top all 4 off with deminiralized water.

 

Than there is no guessing.

 

Also...only use a 50/50 mixture if you live somewhere that it doesn't get below -30*F or -34*C...if it gets colder....your best mixture is 70/30 that's 70% antifreeze, 30% water.

 

It has a freezing point of -60*F or -51*C...and its boiling point is 240*F instead of 225*F

 

 

Also...dont use pure 100% antifreeze...that's only good for 10*F or -12*C

 

Above mixtures of 70% glycol the freezing point goes down. But the more glycol the higher the boiling point.

[minibike132]

I would personally...and I always do....mix my coolant outside the vehicle. I take 2 bottles of 100% coolant and 2 empty bottles, half fill the two empties with coolant than top all 4 off with deminiralized water.

 

Than there is no guessing.

 

Also...only use a 50/50 mixture if you live somewhere that it doesn't get below -30*F or -34*C...if it gets colder....your best mixture is 70/30 that's 70% antifreeze, 30% water.

 

It has a freezing point of -60*F or -51*C...and its boiling point is 240*F instead of 225*F

 

 

Also...dont use pure 100% antifreeze...that's only good for 10*F or -12*C

 

Above mixtures of 70% glycol the freezing point goes down. But the more glycol the higher the boiling point.

 

Good info but I think his issue is that he flushed with water through a T not flush with a machine.

 

A couple of hours of running ought to get you to the point where you are mixed good enough for testing.