Any Partial Coolant Drain Advocates ?

100% YES!

Been doing it this way for 30 years, all the way back to 1990 at the dealers. Drain and fills. That's it.

Right now I let the factory fill go to 80,000-100,000 miles, then I do a simple drain and fill. Repeat every 30,000-40,000 miles there after. Simple.

Never one single issue. I would never try to loosen a block drain, my lord! Just don't do that. And don't waste your time flushing, cleaning...just drain and refill, it will be spotless if you keep up with it.
 
Originally Posted by Leo99
Originally Posted by user52165
Originally Posted by slacktide_bitog
Once you open the radiator drain, you might as well do it all
smile.gif




If only it was that easy.
confused2.gif


Been doing partial drains for years.


I think he meant to drain out whatever comes out of the radiator when you open the stopcock. For my Camry, it's about 1.25 gallons.


Where do you guys take the used coolant to ?
 
Originally Posted by painfx
Where do you guys take the used coolant to ?

Our city recycling center takes it, but the Milwaukee Metropolitan Sewerage District (where our sanitary sewers go) allow dumping down the drain.
 
Originally Posted by kschachn
Originally Posted by painfx
Where do you guys take the used coolant to ?

Our city recycling center takes it, but the Milwaukee Metropolitan Sewerage District (where our sanitary sewers go) allow dumping down the drain.


Down the drain means house drain, not storm (street) drain.

01.gif
 
Last edited:
Originally Posted by user52165
Down the drain means house drain, not storm (street) drain.

Yes most definitely, I wanted to make that clear. And not down the house drain if you have a private septic system.

Also only if your municipal sewerage district permits it.
 
*OP here : For a partial radiator coolant drain - are you opening the radiator drain peacock and "eyeballing" a gallon or so to come out , then adding your fresh 0-50 coolant mixture back into the radiator ?
 
Originally Posted by ChrisD46
*OP here : For a partial radiator coolant drain - are you opening the radiator drain peacock and "eyeballing" a gallon or so to come out , then adding your fresh 0-50 coolant mixture back into the radiator ?

I drain the radiator and recovery tank completely, then refill with a 50/50 mix that I make from full strength coolant and distilled water. The coolant in the cooling system is already 50/50 so I don't over think it.
 
Another topic worth mentioning.....I no longer buy the full strength coolant. I have read conflicting articles about water quality and have tried distilled, deionized, and municiple water allowed to outgas overnight. I dont know what is best, but I now just buy the 50/50 and drain and fill. No sleep lost this way. Every 5 yrs they get done regardless of miles.

Yes you save a little bit buying full strength, but you genuinely don't know the water quality of what you are buying.
 
Originally Posted by Fordiesel69
Yes you save a little bit buying full strength, but you genuinely don't know the water quality of what you are buying.

What, you don't know the quality of distilled water you're buying?
 
It's all I ever do anymore for routine maintenance on all my rigs, drain the radiator, refill and burp and motor on, just do it a little earlier than the specified interval and no problem
 
Drain/refill at 5 years and then every 2/3/4 years after that. I've used tap water and distilled water. What about softened water? I don't want to buy 50/50 although I just bought 55/45 from my Mazda dealer for top off.
 
Originally Posted by kschachn
Originally Posted by Fordiesel69
Yes you save a little bit buying full strength, but you genuinely don't know the water quality of what you are buying.

What, you don't know the quality of distilled water you're buying?

My lord! If we have to worry about the quality of the distilled water, we all are screwed anyway.

The way I see it...using distilled is better than what I used to do. Just add tap and not give it one second of thought. Did that for years without issue, but now I do use the distilled. Figure...it's easy enough to get, it's cheap and everyone says to do it.

But the "quality of the distilled"? This is getting too complicated for me. Lol
 
Originally Posted by demarpaint
Originally Posted by ChrisD46
*OP here : For a partial radiator coolant drain - are you opening the radiator drain peacock and "eyeballing" a gallon or so to come out , then adding your fresh 0-50 coolant mixture back into the radiator ?

I drain the radiator and recovery tank completely, then refill with a 50/50 mix that I make from full strength coolant and distilled water. The coolant in the cooling system is already 50/50 so I don't over think it.


^^^ I resemble this ^^^
But after having a bad experience with a plastic petcock … tend to use a lower hose
 
Originally Posted by ChrisD46
*OP here : For a partial radiator coolant drain - are you opening the radiator drain peacock and "eyeballing" a gallon or so to come out , then adding your fresh 0-50 coolant mixture back into the radiator ?

I did the eyeball method recently on my Titan.
Drained a cold engine via radiator petcock. Refilled with 50/50 blue. Got lucky as one gallon put it right back at the cold fill line on the overflow bottle.
Oh and first time I ever bought pre-mix coolant.
Couldn't find full strength locally.
 
Originally Posted by 4WD
Originally Posted by demarpaint
Originally Posted by ChrisD46
*OP here : For a partial radiator coolant drain - are you opening the radiator drain peacock and "eyeballing" a gallon or so to come out , then adding your fresh 0-50 coolant mixture back into the radiator ?

I drain the radiator and recovery tank completely, then refill with a 50/50 mix that I make from full strength coolant and distilled water. The coolant in the cooling system is already 50/50 so I don't over think it.


^^^ I resemble this ^^^
But after having a bad experience with a plastic petcock … tend to use a lower hose


I resemble this. It can prove to be an interesting day when you have a bad experience with your petcock.
This is why if you look on my tool shelves, you will see extra ones. You know you never need one until you
need one. LOL
 
Originally Posted by 4WD
Originally Posted by demarpaint
Originally Posted by ChrisD46
*OP here : For a partial radiator coolant drain - are you opening the radiator drain peacock and "eyeballing" a gallon or so to come out , then adding your fresh 0-50 coolant mixture back into the radiator ?

I drain the radiator and recovery tank completely, then refill with a 50/50 mix that I make from full strength coolant and distilled water. The coolant in the cooling system is already 50/50 so I don't over think it.


^^^ I resemble this ^^^
But after having a bad experience with a plastic petcock … tend to use a lower hose


I resemble this. It can prove to be an interesting day when you have a bad experience with your petcock.
This is why if you look on my tool shelves, you will see extra ones. You know you never need one until you
need one. LOL
 
*I take it many peacocks are plastic or brittle ? I also suppose turning them carefully with even leverage prevents (or reduces) breakage ?
Originally Posted by Gebo
Originally Posted by 4WD
Originally Posted by demarpaint
Originally Posted by ChrisD46
*OP here : For a partial radiator coolant drain - are you opening the radiator drain peacock and "eyeballing" a gallon or so to come out , then adding your fresh 0-50 coolant mixture back into the radiator ?

I drain the radiator and recovery tank completely, then refill with a 50/50 mix that I make from full strength coolant and distilled water. The coolant in the cooling system is already 50/50 so I don't over think it.


^^^ I resemble this ^^^
But after having a bad experience with a plastic petcock … tend to use a lower hose


I resemble this. It can prove to be an interesting day when you have a bad experience with your petcock.
This is why if you look on my tool shelves, you will see extra ones. You know you never need one until you
need one. LOL
 
Now what do we exactly mean by partial drain.

Doing a simple drain and fill of the whole cooling system without flushing, every x years?

Or draining maybe for example the expansion tank and refilling with fresh coolant to keep the inhibitors , and pH fresh? ( I do that every 3 months or so ) + a drain and fill every 3 years ( i use conventional coolant )
 
Last edited:
Originally Posted by FordCapriDriver
Now what do we exactly mean by partial drain.

On nearly all vehicles approximately 1/2 of the coolant is in the radiator/overflow tank and the other 1/2 is in the engine block. Most here refer to a partial drain as draining and replacing the 1/2 that is in the radiator/overflow tank only. Because today's coolants keep the systems so clean, it is felt unnecessary to do an entire coolant flush. It's similar to just doing a pan drop and refill on a transmission, where 1/2 (+/-) of the old fluid remains in the torque converter, etc..

The logic of the partial drain done more often is that it is just so easy to drain and refill the radiator compared to attempting to flush out the entire engine. And again, we just don't seem to see the crud buildup in cooling systems with the newer coolants like we did several decades ago. Save the complete fluid exchange for neglected systems or when changing coolant types.
 
Back
Top