General coolant flush procedure correct?

[skaughtz]

I'm going to do this for the first time. I just wanted to make sure I'm not confused on something even though this all seems simple enough. Also, I'm just looking to get the old coolant out, a simple one time flush with distilled water, and new coolant in. Nothing fancy. I also purchased a Lisle Spill-Free funnel after hearing such great things about how easy they make the bleeding process.

1) Drain radiator.
2) Remove lower radiator hose to drain block.
3) Fill radiator with distilled water.
4) Turn on car and wait until thermostat opens to cycle through engine (keep adding water while this takes place until full).
5) Drain radiator.
6) Remove lower radiator hose to drain block.
7) Fill radiator with coolant.
8) Turn on car and wait until thermostat opens to cycle through engine (keeping adding coolant while this takes place until full).
9) Wait for air to bleed out of system.
10) Profit.

My main question is whether removing the lower radiator hose will get most of the coolant/water out of the block?

 

[CarbonSteel]

I think this depends on the engine. It did not get all of the old coolant out of my 5.4L by pulling the lower hose. I had to use multiple gallons of distilled water to flush it (along with MC radiator flush). After the distilled water became clear, I dumped all of it again and added the coolant. A couple of weeks later, I drained 1 gallon out and added a 1 gallon of full strength MC Gold coolant to increase the ratio of coolant to water.

 

[HTSS_TR]

I have inclined driveway, I park the car facing the street so that the front is lower.

1) Turn the heat to max - Don't turn off the heat until the job is done
2) Drain radiator and reservoir
3) Fill radiator and reservoir with distilled water
4) Turn on car around so the front is higher and wait until thermostat opens to cycle through engine (keep adding water while this takes place until full)
5) Turn on car around so the front is lower and drain radiator and reservoir
6) Fill radiator with concentrate coolant to 50% capacity, add distill water to full.
7) Turn on car around so the front is higher, add distill water if needed.
8) Add distilled water the next few days if needed.

 

[skaughtz]

I guess mentioning the car would have been smart...

2012 Civic LX. 1.8L engine.

Going to use the Honda Type 2 Blue Coolant (50/50 premixed).

 

[Donald]

You can flush it with water from a garden hose, its only towards the end yous witch to distilled water.

 

[gathermewool]

Why are you changing the coolant so soon?

I've done complete distilled flushes in the past and it was more trouble than I think it's worth, so I'll never put that much effort into it again. Not that this is a relevant excuse, but I've known hundreds of people with high mileage cars who have never changed the coolant.

I like to refresh the additive package and that's about all I care about. Does the anti-freezing/boiling properties of coolant change over time and/or with heat cycles?

//

More specific to your particular car:

I just drained and refilled the radiator in my '08 Civic last year (~100k miles) with OEM 50/50, and plan to do so again in 40-50k miles. I don't believe Honda requires a flush, nor does it require such frequent changes.

 

[skaughtz]

Originally Posted By: gathermewool
Why are you changing the coolant so soon?

I've done complete distilled flushes in the past and it was more trouble than I think it's worth, so I'll never put that much effort into it again. Not that this is a relevant excuse, but I've known hundreds of people with high mileage cars who have never changed the coolant.

I like to refresh the additive package and that's about all I care about. Does the anti-freezing/boiling properties of coolant change over time and/or with heat cycles?

//

More specific to your particular car:

I just drained and refilled the radiator in my '08 Civic last year (~100k miles) with OEM 50/50, and plan to do so again in 40-50k miles. I don't believe Honda requires a flush, nor does it require such frequent changes.


The car has about 50k miles on it, and I am just a fan of preventative maintenance when it comes to fluids. Fresh fluids make me happy

The reason I wanted to flush the system rather than just drain and refill the radiator is because I think about 20k miles ago my wife took the car to a quick lube place and they no doubt used some bulk coolant for a radiator drain and fill. It is probably just paranoia, but I have read enough anecdotal stories regarding the importance of Honda fluids in Honda vehicles. It is something I stick to other than the engine oil. So at 50k I figured a one time flush and refill of the whole system with Honda coolant would probably not be a bad thing. I'll do it again at 100k.

 

[mclasser]

I did a complete coolant flush on my I35 not long ago using distilled water. Pulling the lower rad hose won't necessarily drain the block. The engine has drain plugs for this but they're usually hard to get to/seized on.

Your procedure is correct but if you want to do a COMPLETE flush, you'll need several (5+) gallon jugs of DI water. When the fluid drains clear, you'll know you got nearly all the old coolant out. When it comes time to finally fill the rad, use 100% antifreeze so you'll be at/close to 50/50 in the system. Filling only 50/50 in the rad with pure water still in the engine block will throw off the mixture. The challenge is finding an Asian coolant in full concentrate, though. Honda blue is only available in 50/50. I ended up just using *gasp* regular Peak Long Life because I know I'll religiously change the coolant every 2 yrs.

 

[skaughtz]

Originally Posted By: mclasser
I did a complete coolant flush on my I35 not long ago using distilled water. Pulling the lower rad hose won't necessarily drain the block. The engine has drain plugs for this but they're usually hard to get to/seized on.

Your procedure is correct but if you want to do a COMPLETE flush, you'll need several (5+) gallon jugs of DI water. When the fluid drains clear, you'll know you got nearly all the old coolant out. When it comes time to finally fill the rad, use 100% antifreeze so you'll be at/close to 50/50 in the system. Filling only 50/50 in the rad with pure water still in the engine block will throw off the mixture. The challenge is finding an Asian coolant in full concentrate, though. Honda blue is only available in 50/50. I ended up just using *gasp* regular Peak Long Life because I know I'll religiously change the coolant every 2 yrs.


Ah nuts to it then. I'll just do the radiator drain and refill. If I keep up with 20/30k intervals it should displace enough of the non-Honda fluid pretty quick and it shouldn't need a flush anyway

 

[Drew99GT]

Originally Posted By: skaughtz
I guess mentioning the car would have been smart...

2012 Civic LX. 1.8L engine.

Going to use the Honda Type 2 Blue Coolant (50/50 premixed).


If you use 50/50 premixed coolant, your water to coolant ration is going to be massively diluted with water with the above procedures, if you flush the system with distilled water and refill with premixed coolant. You'd need to use concentrated coolant if you flush it, as mostly water will be left in the block.

It has a block drain according to Google; you could try removing it. If it's really tight/hard to remove, leave it as stripping it will put you in a world of hurt.

So if you can't purchase 100% Honda concentrated coolant, I'd just drain and refill the radiator and call it good. maybe do it twice this year, and then once every other year or something. I've done that with my Corolla and it's still bright and shiny inside the radiator and engine after 180,000 miles, and with most vehicles, the cooling system will be opened up for something at some point down the road where the entire cooling system will be refilled with new coolant (water pump goes bad, a gasket needs replacing etc.).

 

[slacktide_bitog]

The Lisle funnel is awesome and essential!

However, it is way too early to change the coolant in that 2012 Civic. Wait until the MM says it's time.

Only use OEM coolant or equivalent (like Pentofrost A3 or Recochem blue)

 

[skaughtz]

Originally Posted By: Drew99GT
Originally Posted By: skaughtz
I guess mentioning the car would have been smart...

2012 Civic LX. 1.8L engine.

Going to use the Honda Type 2 Blue Coolant (50/50 premixed).


If you use 50/50 premixed coolant, your water to coolant ration is going to be massively diluted with water with the above procedures, if you flush the system with distilled water and refill with premixed coolant. You'd need to use concentrated coolant if you flush it, as mostly water will be left in the block.

It has a block drain according to Google; you could try removing it. If it's really tight/hard to remove, leave it as stripping it will put you in a world of hurt.

So if you can't purchase 100% Honda concentrated coolant, I'd just drain and refill the radiator and call it good. maybe do it twice this year, and then once every other year or something. I've done that with my Corolla and it's still bright and shiny inside the radiator and engine after 180,000 miles, and with most vehicles, the cooling system will be opened up for something at some point down the road where the entire cooling system will be refilled with new coolant (water pump goes bad, a gasket needs replacing etc.).


Yeah, definitely don't want to bother with trying to get the ratio correct since it is the wife's car and I won't hear about anything being wrong until the engine overheats and dies three weeks from now on a 100 degree day

Now that I've thought about it the radiator drain and refills should be plenty. Thanks all.

 

[Chris Meutsch]

Originally Posted By: skaughtz
I guess mentioning the car would have been smart...

2012 Civic LX. 1.8L engine.

Going to use the Honda Type 2 Blue Coolant (50/50 premixed).


Nah, just drain the radiator and refill with Type 2. That's what I do and have done for years on my Honda's. No issues.
You would be going the extra mile and it wouldn't hurt but why spend the time?

 

[EdwardC]

Looks like you already decided to just do a DnF, but that's exactly what I would have suggested anyway. I wouldn't do more than that, especially if you plan to use OEM Type 2 that's (for the most part) only available as a premix.

I'm curious, does the coolant color see to be anything other than the OEM blue?

Good luck with the drain and fill!

 

[Kawiguy454]

...I dont see anywhere the step by step so be sure to bleed air from any bleed screws you may have on the top of the engine after you refill. An air pocket in the engine can blow a head gasket. Don't ask how I know this :-(

 

[AndyinAL]

I would not touch the lower radiator hose. It is no lower than the drain on the radiator. chances are it will not leak a drop in the next 10 years. All bets are off when you start messing with it. I would do it at my leisure over the course of several days, draining the coolant when it is cool and refilling with distilled water until you get fairly clear water draining out. Should only take 3 or 4 times. I like to do mine in my sloped driveway with the car facing downhill making the radiator even lower.

Verify total coolant capacity. Go to Pepboys and buy 1 gallon of blue concentrate made by Reochem. ($20 without any discount).

Do a final drain. Whatever the total system capacity is, put in HALF that much antifreeze concentrate. Top off with distilled. Start and run with cap off, heater valve open, monitoring level. I like to do this with the car pulled in the driveway with the radiator cap higher than the engine. Your Honda may have a bleed screw or some other final purge procedure. YMMV

 

[901Memphis]

If the system is not full of floaters and clean I would just do one drain and fill of the radiator... No flush is ever needed if you stay on top of it before it gets bad.

 

[Rand]

Many times Draining and filling is much easier to do, Esp. when the system isn't neglected.

If you want to be OCD drain and fill once a year for a 3-4 years.

 

[gathermewool]

I forgot to mention that the coolant that came out of my '08 Civic LX appeared very clean and looked very similar to what I put back in.

Can you find out for sure whether the quick-lube place drained-and-filled with non-OEM fluid? If that is the case, then I'd definitely be flushing the coolant system. At the very least, performing three drain-and-refills in rapid succession.

It might be that they still have you in their system and can tell you for sure when they did it and what they used.

//

If you're simply worried that they suckered her into doing it, but neither she nor you are sure, then I'd follow your new plan to drain-and-refill the radiator every 20-30k (for your peace of mind, of course...)

I'll end by saying that, if you've only got the initial OEM fill of coolant in there, then your peace of mind ratio is way off, since 50k is ridiculously short. Following that, if you do change it now, then your subsequent 20-30k miles drain-and-fills is also ridiculously short. There, I've said and won't say it again.