2017 gmc sierra Coolant flush

[Eramo77]

I have a 2017 sierra 1500. 5.3l. I would like to do a full engine coolant flush, any tips? I've seen some videos online, where the petcock was opened and drained. Could I also drain it through one of the radiator hoses? Does anyone know the total amount of coolant needed for a full flush? I will buy concentrate and mix it with distilled water to make a 50/50 mix. 

[CamGTP]

You'll never get it all out without a flush machine because draining the block is hard.

 

I've done it the redneck way. Remove the lower hose and remove the thermostat, stick a garden hose in there and turn it on. That will flush it pretty good, then just drain the radiator.

 

2 gallons of concentrate should be enough when you mix it with water.

[reardiff]

How important is using distilled water?  I was thinking of doing a flush using the garden hose method then using pre-mixed 50/50 coolant, but we have terribly hard tap water. How much does the block hold?   Is the 5 year 100k intervals still what's recommended?

[CamGTP]

Depends on who you ask. I've done more coolant flushes with regular hose water or softened water from the laundry room sink than I have with distilled water.

 

The block holds at least 1 to 1.5 gallons of coolant. You can force most of it out with an air hose too, just use something or your hand to block the air from escaping where you are putting the air in.

[Black02Silverado]

The coolant system takes 16.6 qts.  You can look it up here.

 

You can use the hose but distilled is highly recommended.  I flushed mine with the hose and then filled it up with the 50/50 mix.  Filled it up and got it up to temp to make sure it was full, then when it cooled I drained the radiator and refilled it again. Overkill probably but it is what I wanted to do.