Dumb questions about coolant system flush

[Mastiff]

Need to replace a radiator and so seems wise to do a full system flush on an old truck. But I'm confused. I understand if I just open the drain on the radiator, that'll leave at least half the total capacity in the block. So if I put the flush stuff in, run, drain, fill with water, run, drain, repeat... when I'm done, now I have a block full of hose water. How do I get it out? It doesn't need to be perfect, but if it's like half the capacity of the system, that's a ton of hard garden hose water in there. The thing I'm not sure about is whether there is a big difference when the lower hose is removed? All the instructions online are a little vague on the details. And I can know the total system capacity, but what I really want to know is how much coolant I'll need with a normal flush. Coolant isn't super cheap these days.

 

[kennyw]

Tap water is ok as long as you do a final flush with distilled according to this video:

How to Flush a Radiator

Keep your engine running cool with maintenance to the cooling system. This step-by-step guide shows you everything you need to know to do the job right.

www.autozone.com

 

[kennyw]

I'm guessing the final flush is just a drain and fill with distilled water a couple of times. Or, buy several gallons of distilled water and skip the tap water.

 

[nvrenuf]

Is using distilled water a west coast thing or a perfect world scenario?

I spent 15 years in parts at a dealership and never saw anyone use (or ask for) anything different than tap water - this was even back during the Toyota V6 head gasket plague. If you’re servicing the coolant on schedule with the correct product it should be fine.

 

[kennyw]

Distilled water is cheap and doesn't have the risk of contaminants such as minerals that accelerate corrosion, tap water does but modern antifreeze also contains additives to help counteract the issues so long as it is serviced more often. But it does not surprise me if dealers ignore the procedures from the OEM and use tap water either.

 

[Wes Harden]

remove the t stat, undo top and lower hose run garden hose into top hose. This will back flush the block. When water come out clear your good. If you wist to drain the block, near the oil pan in the middle of the block on each side are two 1/4 npt plugs that will drain the water jacket. You may need to dig out rust to make them drain.
If you know the total capacity you want 50/50 mix of anti freeze and water. Distilled is best. I buy concentrate mix with distilled water.

 

[76zimmer]

As Wes says….use those block drains and distilled h20 for the best scenario!

 

[dyeager535]

Yep. Distilled water is the best for replacement. Additives in the coolant are designed to counteract the effects of contaminants in the cooling system, but the additives are what wear out in coolant (fun fact: antifreeze never stops being antifreeze) Using distilled water means you'll have the minimum amount of contaminants possible in the coolant system to start with, thus the additive package will not be "used up" as fast.