coolant capacity of radiator vs. block

I need to flush my cooling system, and I did read the How To post, which involves flushing it through the bleeder bolt. That might be a little messy for me, as I don't want the old coolant in the driveway. Probably I'll just drain the radiator, a couple of times if I have to.

My question is: I know there is a drain bolt for the block. If I don't mess with it, relatively speaking, how much coolant am I missing by just draining the radiator? 25%? Maybe I'll just drain the radiator, refill with some flush, run it, refill with a weak solution of anti-freeze (trying to keep the flash rusting away), then drain again and refill with a somewhat more than 50-50 anti-freeze/water, to compensate for the mostly-water in the block. I'm wondering how much more than 50-50 to do, which is why an estimate of the volume of the block compared to the radiator would be good to know.

Thx

I'm just going to add a few things. You flush the radiator with "radiator flush" through the pet-cock on the bottom of the radiator, not the bleeder bolt.

After you do flush the system out, make sure you bleed out all the air through the bleed bolt by the thermostat. I'm not sure what your asking, but little more anti-freeze, 60/50 is better for deteroation.

Quote:

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Originally Posted by ddude2uc

I'm just going to add a few things. You flush the radiator with "radiator flush" through the pet-cock on the bottom of the radiator, not the bleeder bolt.
After you do flush the system out, make sure you bleed out all the air through the bleed bolt by the thermostat. I'm not sure what your asking, but little more anti-freeze, 60/50 is better for deteroation.

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hate to be a smart ass but i think you ment 60/40....well once my rad poped i just filled it with coolent and i lost my heater....i was running mostly coolent...i put some water in and my heater started to work again.

The water's what does the cooling. The coolant just raises the boiling point and lowers the freezing point.

OK, I guess I need to restate my question.

I did read the "How To" on flushing the system, but I don't want to do it that way, as it might make too much of a mess in the driveway. I plan to do this:

1. drain the radiator, but leave the block drain alone. I don't know how much "old" coolant this will leave in the motor. I'll add the bottle of Prestone Radiator flush, fill the radiator back up with water, bleed the system, and drive around for 20 minutes or so after the temp comes up.

2. wait for the water to cool off a bit, then drain the radiator again, refill with a weak solution of antifreeze/water (I'm concerned with flash rusting if its all water), bleed system, and drive around again until it gets hot.

3. Do I do this a third time, or is twice good enough? I guess it would depend on what the capacity of the block compared to the radiator is. If the block is 25% of the total, then by the second round I will have gotten rid of most of the old coolant. 3 rounds will surely purge almost all of it.

4. Refill with a 60/40 mixture. Bleed and check concentration. Adjust if necessary.

If you're worried about mess, just take an empty milk or water jug and cut the top off. Two of those will hold all the fluid you need without all that effort.

I'm thinking that by the time the couple of gallons of coolant drains down across the various hoses and other things, it will go in different directions. If I thought I could use container as you suggest I'd sure do it, but I think it wouldn't work.

It works.
When I took my tranny out I had to disconnect hoses. What you can do is just disconnect hoses and point them downward individually. Still easier that draining and refilling the radiator a bunch of times.

to answer your original question, i think there is a bit more coolant in the block than there is in the radiator. or at least that's how i remember it being from the times i've drained them seperately.

If your worried about all the coolant getting out so you can start off with clean anti-freeze, either remove the thermostat & bleeder valve..
Open up the petcock on the lower end of the radiator & use a blow gun tip wrapped in shop rags & blow a shit load of compressed air through the radiator cap. Should get most if not all the fluid out.

Double snatch post.