Replacing radiator coolant -Whoops! Only 1/2 came out??!!

[Muse]

Please see my last post, #15, made at 5:07 PM PDT.
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I'm overdue (probably) to replace my radiator coolant and want to do it this afternoon. My 1997 Mazda 626 LX's (2 liter engine) manual says it has aluminum and I should use an ethylene glycol based antifreeze, and 50-50 if conditions warrant, higher if really cold but if temperature will stay above around 3 F, I can use 35% antifreeze. I'm unlikely to encounter conditions even that severe.

In another thread here someone said to use premixed 50-50. I've never heard of premixed before. What is that and why would it be better than getting a gallon of ethylene glycol based antifreeze in a gallon container and add water?

Should I buy a gallon of distilled water for this or use my Berkeley, CA tap water? The water here isn't very "hard." I'm going to make a stop at Kragen's this afternoon.

My radiator's capacity is 7.4 qt.

1. What should I get?
2. Should I get a gallon of distilled water too?
3. When I drain the radiator (into a pan, will bring to a place that accepts in gallon containers), should I then flush the radiator using a garden hose?

The manual includes detailed instructions on how to change the fluid (i.e. run the motor at such and such RPM for a few minutes, repeat, etc.), then says to have a competent mechanic do the job if you lack expertise, kind of a weird thing to say. Well, I guess they have their reasons but they don't say. When I talked to my mechanic about it a few years ago he said he'd charge me ~$100. I'd like to save myself that expense.

 

[Vic Vega]

Refill the system with 50/50 coolant/water. Don't use tap water. Almost all the coolant sold at auto parts stores or places like Target/Walmart is already a 50/50 mixture right in the jug.

 

[Muse]

Refill the system with 50/50 coolant/water. Don't use tap water. Almost all the coolant sold at auto parts stores or places like Target/Walmart is already a 50/50 mixture right in the jug.

So, I'll need 7.4 qt. Is it sold in 2 gallon jugs? Kragen's on the way home. Is it worth it to go ~5 miles out of my way to hit up Target for it? Walmart's a lot further.

I do want to do the flush thing?

 

[Vette73]

Cheaper to buy the full strength antifreeze, then the 50-50, and mix yourself. Since you have not filled out where you live in your profile I have no idea if 50-50 will work or not but that is what I use for all my cars. So I would buy 1 gallon of antifreeze and mix with water. Tap is fine for most unless you are on a well or have bad water.
Also a good time to replace/check your thermostat, radiator cap, and hoses.

 

[Zap]

Distilled water isn't that expensive. Costs about 75 cents/gallon at my local supermarket for steam distilled.

 

[Kaervak]

If you're doing a full system drain/flush buy a gallon of pure antifreeze, pour the entire gallon in and then fill the reservoir with the distilled water as necessary. You'll end up with a little stronger concentration than 50/50, but it won't harm anything. If you're just draining and flushing the rad, get the 50/50.

 

[me4get]

Any car with aluminum parts: NO LESS than 50/50. or corrosion with happen.

 

[Muse]

Cheaper to buy the full strength antifreeze, then the 50-50, and mix yourself. Since you have not filled out where you live in your profile I have no idea if 50-50 will work or not but that is what I use for all my cars. So I would buy 1 gallon of antifreeze and mix with water. Tap is fine for most unless you are on a well or have bad water.
Also a good time to replace/check your thermostat, radiator cap, and hoses.

I mentioned in the OP that my water is Berkeley, CA tap water.

Well, I just saw this. Wasn't able to check the thread, but on my way home early this afternoon (a bit over an hour ago), I drove over to Target and spotted two possibilities:

50-50 Peak - 1 gallon for $8.29
Concentrated Peak (i.e. undiluted) - $10.49

Clearly, the concentrated is the better deal, so I bought it along with a gallon of distilled water for $0.99 + CRV + tax (I assume they charged tax)

By virtue of your post, maybe I can use tap water and save the gallon I bought for the upcoming earthquake. :\ I don't think the water here is "bad."

There's a car in front of my house right now, but if they move it, I'll hopefully be able to snatch the space, because I'd like to flush my radiator into the gutter and not my driveway. The Peak antifreeze has instructions on how to flush the radiator. Says to fill the radiator with water and run the engine with the heater turned on high for 10 minutes, IIRC.

I don't know how to check my thermostat, but I can at least look at the radiator cap and inspect the hoses. The car is little used, just 23,000 miles on it (1997) and I'm using it around 1200 miles/year, 1500 tops.

 

[Muse]

If you're doing a full system drain/flush buy a gallon of pure antifreeze, pour the entire gallon in and then fill the reservoir with the distilled water as necessary. You'll end up with a little stronger concentration than 50/50, but it won't harm anything. If you're just draining and flushing the rad, get the 50/50.

I don't understand the distinction. Aren't both drain and flush?

Do you mean doing one with the engine running when flushing and the other without?

 

[Vette73]

^

Yea then 50-50 will be fine.

DON'T drain into the gutter. Collect it and see if there is a recycle center near you. If not then pour it down your sink/toilet. You can use a old milk jug or 2 liter bottle. Draining it down the gutter is illegal.

 

[Muse]

Any car with aluminum parts: NO LESS than 50/50. or corrosion with happen.

The manual says if temperatures won't go below 3 F, I can use 35% antifreeze. Yes, the manual says it has aluminum parts. However, I figure I'll add ~50% antifreeze anyway. I figure it will give longer/stronger protection from corrosion. I hope the engine hasn't suffered corrosion already. I think it's overdue for the treatment.

 

[kornphlake]

I don't think you're supposed to dump antifreeze in your gutters or storm drains, but I'm not sure who recycles/decontaminates coolant. You might want to do some more research before you let it drain into the gutter.

 

[Muse]

^

Yea then 50-50 will be fine.

DON'T drain into the gutter. Collect it and see if there is a recycle center near you. If not then pour it down your sink/toilet. You can use a old milk jug or 2 liter bottle. Draining it down the gutter is illegal.

No, no I wasn't going to drain it down the gutter, but into a large plastic pan and from there pour into 2 one gallon milk containers and deliver to a facility that will accept the used fluid (see OP). What I intend to do unless people tell me it isn't a good idea is to flush into the gutter, after draining the radiator as much as possible into the pan. There will be some used antifreeze in the flush, but only a very small percentage of what's in the system now, I believe.

I was driving until about 1.5 hours ago. I don't know if the engine's cool enough to proceed now. I'm wondering about a few things:

1. OK to flush into the gutter (after catching what drains before the flush)
2. Do I need a flush solution? One site says I should buy radiator flush. I don't recall seeing that in the car's manual. (edit: I suppose that's if your radiator is particularly dirty)
3. How long do I need to let the engine cool before I can start doing this stuff? One site says "cold." But I really want to do it today. How many hours do I need to let it sit? Are 2 enough?

 

[kornphlake]

I can't tell you what to do in your gutter, but I agree that the coolant would be dilluted if you are only draining the system after flushing with tap water. Depending on how many times you plan on filling and draining the system and how many containers you have on hand it might not be that big a deal to just catch all the water that has come in contact with coolant, I think my car holds about a gallon of coolant.


I don't think it's really necessary to use a radiator flush, consult your manual, it might say to use dish soap or it may say nothing at all. I have read that some of the commercial radiator flush products can cause more problems than they solve, do some research if you choose to use one product or another. One product in particular (I can't remember which) had many reports of causing the intake manifold gasket to fail.

I've drained and refilled my car when the engine is still warm. You probably don't want to dump ice cold water into a steamy hot engine, but if it's been sitting for a few hours that's long enough. Your mechanic isn't going to let it sit in the bay all day waiting for it to cool off. The reasoning behind wanting the engine to be cool is two fold, 1) you don't want to risk cracking a hot block with cold water (although I'll admit this is a fairly remote possibility) 2) if you open the cooling system when the engine is hot then seal it back up when it's hot you can create a vacuum in the system as the coolant cools and contracts, this can cause the radiator to crack as it is designed to be under pressure rather than a vacuum. I don't think you need to go to too great of an extreme waiting for the engine to cool, as long as it has been sitting for a while and you're not uncomfortable reaching around the radiator to open the stopcock it should be fine.

 

[Muse]

I just drained the coolant, and it looks like only ~1/2 came out! The capacity is listed as 7.4 US quarts and only enough came out to fill a gallon milk container, with about a cup to spare. What's up with that? I haven't flushed with water yet. What should I do? Is 1/2 of the old coolant stuck in the engine? The radiator dipstick showed full before I started all this... If anything, the front of the car is a little lower than the rear, it's on a slight grade.

 

[marvdmartian]

Yes, both the engine and the radiator are full of coolant. That's why they recommend you refill with water and run the engine, as it will flush the old coolant out of the engine block, as well as dilute it more.

Chances are, once you drain it the 2nd time, it might only take the gallon of antifreeze. Not a problem, since what's in your engine block will be mostly water, and once you turn the engine back on, it will mix as it runs through the coolant system.

 

[Muse]

Yes, both the engine and the radiator are full of coolant. That's why they recommend you refill with water and run the engine, as it will flush the old coolant out of the engine block, as well as dilute it more.

Chances are, once you drain it the 2nd time, it might only take the gallon of antifreeze. Not a problem, since what's in your engine block will be mostly water, and once you turn the engine back on, it will mix as it runs through the coolant system.

Thanks. Man, they don't tell you that! Most instructions don't say to turn the engine on, just fill with water and drain, then fill with 50-50. I've hit a site or two, looked in my manual and Chilton's. None says to turn on the engine. The site I looked at really was Castrol.com, and printed out their instructions.

The fluid I drained looks nice and clear, so maybe I shouldn't be too concerned with getting it all out, just getting the new gallon in, eh?

Just run the engine a minute or two? Enough to circulate the fluid but not get the engine/coolant so hot I can't immediately remove the radiator cap and drain? I'd like to finish this in an hour, 2 max...

 

[bruceb]

You do not actually run the engine. Disable the ignition (fuse) and put the Heater on HOT
Then just crank the engine about 30 seconds or so. Most of what is left in the block and heater should come out. The use of 50/50 premix is so you do not mess up when trying to mix it yourself. Prestone has it and that ratio is just about perfect for most climates. If you do mix it yourself, use distilled water as it has less minerals and will keep the cooling system cleaner. Do not forget new radiator cap and thermostat. On new cars, you need to get all the air bubbles out, usually a bleed valve at highest point in system. See your service manual for details.

 

[Muse]

You do not actually run the engine. Disable the ignition (fuse) and put the Heater on HOT
Then just crank the engine about 30 seconds or so. Most of what is left in the block and heater should come out. The use of 50/50 premix is so you do not mess up when trying to mix it yourself. Prestone has it and that ratio is just about perfect for most climates. If you do mix it yourself, use distilled water as it has less minerals and will keep the cooling system cleaner. Do not forget new radiator cap and thermostat. On new cars, you need to get all the air bubbles out, usually a bleed valve at highest point in system. See your service manual for details.

Service manual? I don't have that, I have the Chilton's? I can get the service manual?

This is the first I've heard of disabling the ignition. Sounds smart, very smart. Well, I've about finished. It's sundown now, dark and cold outside. Well, colder.

I have no idea how you're supposed to get a 50-50 solution in there using premixed. Wacky given that so much remains in the system unless maybe if you do a trick like the one you describe here.

I did get most of the AF out of the system, I'd say at least 90-95%. I just filled it as much as I could with concentrated AF, then put the radiator cap on and ran it at idle for 10 minutes. Don't want to mess more with it tonight. I'll drive it around 6 miles tomorrow (up 800' and back down), and check and add more fluid (some more concentrate so I've added at least 3.5 qt, and if there's still room, some distilled water). I'm sure it's at over 40% AF now. There's less than a qt left in the gallon concentrate bottle.

 

[kornphlake]

Did you slide the climate control lever to hot when you drained the radiator? Some cars have a valve that blocks the hose going to the heater core and will hold some coolant in the heater core unless the valve is opened (~1 qt.)

Did you remove the radiator cap before you opened the stopcock? With the cap on the radiator only so much will drain before a vacuum builds in the radiator and it won't drain anymore.

Normally the thermostat will be closed when you drain the coolant on a cold engine, if the thermostat is in good condition it may hold a vacuum on the engine block when the stopcock is opened. I usually drain as much as I can, close the stopcock, refill then start the engine and run it up to operating temperature so the thermostat opens which will mix the remaining coolant with fresh water and dillute it a bit more. Drain, refill and repeat until the coolant drains clear enough for your standards.

Unless you live in an extreme climate I don't think it's really necessary to fuss the mix of anti-freeze to water. As long as you've got at least 20-30% anti-freeze you should be okay.

 

[Muse]

Did you slide the climate control lever to hot when you drained the radiator? Some cars have a valve that blocks the hose going to the heater core and will hold some coolant in the heater core unless the valve is opened (~1 qt.)

Nope. Nobody told me to do that, no site, no book. They only said to put the heater on high later, when bleeding/topping.

Did you remove the radiator cap before you opened the stopcock? With the cap on the radiator only so much will drain before a vacuum builds in the radiator and it won't drain anymore.

Yes, removed the cap before doing anything.

Normally the thermostat will be closed when you drain the coolant on a cold engine, if the thermostat is in good condition it may hold a vacuum on the engine block when the stopcock is opened. I usually drain as much as I can, close the stopcock, refill then start the engine and run it up to operating temperature so the thermostat opens which will mix the remaining coolant with fresh water and dillute it a bit more. Drain, refill and repeat until the coolant drains clear enough for your standards.

How long do you wait before removing the radiator cap and petcock after running the engine that long?

The reason I didn't run the engine longer each time after putting in as much tap water as I could after each drain was that I didn't want the radiator to get too hot. I wanted to finish the job yesterday evening, before it got dark. I ran the engine a minute, tops. I suppose the thermostat never opened and a lot of the fluid never drained, was locked in the block. :'( Oh well. Next time I'll know better (will save this thread).

Unless you live in an extreme climate I don't think it's really necessary to fuss the mix of anti-freeze to water. As long as you've got at least 20-30% anti-freeze you should be okay.

I figure I've definitely got over 40% right now, probably closer to 45% after I top up this afternoon. A lot of the old fluid/water is still in there, but the stuff I drained out looked pretty clean to me so maybe it's OK. :\

 

[boomerang]

Sometimes one starts out on a quest to save money and it ends up costing more when the job is done.

Right now, you have a mix of old and new coolant. To top it off, you're guessing at the mix ratio. It's your car and if you're happy with the results, I guess that's all that matters.

 

[desy]

Thats why I don't care for the 50/50 unless you plan to flush with it, I put the garden hose to it, flush it all out fill it up, drive, drain it and put concentrate in, knowing there is all kinds of water in the block to dillute

 

[LTC8K6]

They make coolant testers and they are cheap, no?

 

[imagoon]

Those engine have a block drain. Your mechanic will often use that as well as the radiator drain to empty the system. Heater to "hot" and those 2 drains with get the system pretty dry.