Coolant replacement
 

Hey guys,

On my 03 Civic, I am not sure if the previous owner had used Honda Coolant. I have had this car for 5 years and want to drain and replace it with Honda Coolant. How do I get everything out without flushing it? I'm trying to do this at home. If I drain the existing coolant replace it with Honda coolant drive it for few days, drain it again and replace it. Will that do the trick?

The reservoir is hard to get to, how do I suck everything out of reservoir without removing it? Any guidance you can provide.

Re: Coolant replacement
 

Reservoir: Make sure the radiator is completely full. Open the radiator drain valve but do not remove the radiator cap. The reservoir should slowly empty first.
After the reservoir is empty then you can remove the radiator cap to speed up draining the radiator.

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Drain radiator.
Refill radiator with new. Burp system as necessary.

During a radiator drain, approximately half of the liquid in the system will stay in the engine and heater areas, so each drain and fill ends up effectively diluting that which remained.
Repeat as often as you wish.

Re: Coolant replacement
 

When engine is cold?

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After burping does the engine need to cool down completely before repeating procedure?

Re: Coolant replacement
 

Cold or hot doesn't really matter IMO but it's safest to do it cold, no risk of scalding hot pressurized liquid. I really see no good reason to do it hot other than the time crunch factor in a shop.



Again, cold or hot doesn't really matter.
If OP is doing multiple D&F back to back, the engine needs to be run through full warmup (radiator fans cycle twice) after each fill to circulate and mix coolant before the next drain.

After final burping/fill/top off, the reservoir level check and adjust should be done after complete cooldown because liquid will be sucked out of the reservoir during cooldown.

Re: Coolant replacement
 

I asked because my untrained mind thinks..besides potential scolding of opening radiator drain valve while hot:
No damage will be done by emptying half of coolant while engine is hot? and/or can it be damaging to add ambient temperature water while engine is hot?

I've either used a flush and fill kit or removed the thermostat...but your method makes it easier to achieve the same thing. Plus leaving a F & F kit on increases chances of leaks. I purchased coolant three weeks ago and intend to do a drain and fill soon per your method. Thanks ezone and OP.

Re: Coolant replacement
 

Yet another reason to wait until it's cooled off LOL



In routine services, I've never witnessed an issue doing it from warm or operating temperature.

OVERheated is a completely different story though. Thermal shock is real.
And on the 8th day God invented the radiator drain, and decided it was good.

Re: Coolant replacement
 

thanks for the clarificaion. roughly how long does an engine take to cool enogh for safe radiator drainage?

petcock :giggle:

Re: Coolant replacement
 

A) WWSWD?


B) Depends on your personal pain threshold.

C) If you wear PPE you wouldn't have to worry about much at all.


Politically correct: Pet Chicken

Re: Coolant replacement
 

Just tried the Ezone method of coolant system drain & fill and I'm pretty dissapointed..I got a few beads of coolant mix on my fingers throughout the whole process..LOL.

Easiest, bestest method (IMO)..thanks again Ezone. Did three drain and fills using distilled water through radiator drain plug..bleeding air in between. Final fill with Pentosin A3 (blue). Will do it this way from now on no matter which vehicle. No mess, didn't crawl under car.

Re: Coolant replacement
 

Which method is that? I forget stuff you know!Where's your PPE? Blue gloves could have saved you from all that pain and discomfort!

Re: Coolant replacement
 

See reply #2 in this thread. Though I modified it using distilled water for three D & F's before adding 50/50 mix. After a few days I will do one more D & F adding coolant mix and then test pH level. Living in mid-west Florida a higher water to coolant mix may be more desireable over 50/50 ratio?

Prior owner purchased an aftermarket radiator, slim fan and slim-can reservoir shown in this link: https://www.jhpusa.com/store/pc/view...dproduct=11122 The hose between the top of radiator and reservoir was almost fully clogged. Removed it and the reservoir and cleaned both to allow better flow.

I stated a few drops in jest. Usually when I do a flush method it seems like I take a mini shower in coolant mix..pulling off radiator hoses, removing thermostat, etc.. During your method I barely got any mix on me and temp not too hot since I proceeded slowly.

I let the engine completely cool during the first two D & F's..on the third one I got impatient and only waited an hour after bleeding air. When I replace my mom's timing belt and coolant replacement soon I will wait an hour or so between each D & F + air bleed.

Re: Coolant replacement
 

did you run the engine with the water in there?

if so, i wouldn't have done that, you probably have a lot of water still in the system, there is lots of coolant in the engine that never drains out,

Re: Coolant replacement
 

Yes. That's where the pH test will come in. I may have to purchase pure anti-freeze (not premixed) and combine as needed to balance it out.

Between the three Civics all the anti-freeze will get used. My thinking was that a gallon of distilled water is 85 cents and gallon of pentosin antifreeze is a minimum $10. Plus I didn't know exactly how many D & F's it would take to get the old coolant looking clear. The mistake I made was purchasing 50/50 instead of pure antifreeze before starting on this. I didn't feel like taking the time to return it and purchasing pure at another store. However, as I mentioned it will all get used.

Re: Coolant replacement
 

You're in Florida, you probably don't have to worry about freeze protection very often.

Re: Coolant replacement
 

Yes..not much of a concern.

If it's diluted to say 70% water and 30% coolant would there be diminished corrosion protection and water pump lubrication?

Re: Coolant replacement
 

It's sure better than straight water
I can't tell you much more than that....Google it?

50/50 is generally considered ideal unless you're far north where temps dip far below -40f.

Re: Coolant replacement
 

Let's not forget the most important thing...blue dye looks cooler than green...lol.

Re: Coolant replacement
 

How much replacement coolant (mix) is required for each drain & fill?

Re: Coolant replacement
 

When I had the 2010 done, ordered 2 gallons of Type II Blue and have some leftover to top reservoir due to evaporation.

Re: Coolant replacement
 

Thanks Craig!