Changing my Coolant

[stackman1]

Hello Everyone. I have a 2002 Impreza OBS and was going to change my coolant. Done way too much reading  but I was about to buy the Peak Long Life concentrate as it seemed the best match. But then I came across the the Subaru Coolant Conditioner that is suggested as an additive. Sounds like it is a good idea.  I am getting a bit of head gasket leakage and it sounds like this could only help.  

 

Anyway I found it on Amazon and when I was there I also spotted what looked to be the OEM coolant from Subaru itself.  I was surprised/suspicious that the Subaru Concentrate is more than 50% cheaper than buying the Peak Long Life at an Autozone? I have included links. 

 

Couple of questions:

1. Does my 2002 Impreza OBS have a bleeder valve to release the air in the coolant system or anyone have a link for the best way to bleed air on when refilling?  (I have seen such valves on YouTube videos for other cars - but don't see it listed in my Haynes manual).

 

2. Any reason not to buy the inexpensive Subaru Coolant Concentrate (beyond my paranoia?)

 

Thanks

Peter

 

http://www.amazon.com/gp/product/B007L72U1C/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=A12WOLQM5J3T6R

 

http://www.amazon.com/Subaru-SOA635071-Coolant-System-Conditioner/dp/B00IGZP2UE

[Rooster2]

Subaru Coolant Conditioner is simply a "stop leak" product. It does an excellent job of stopping minor seepage, that I surmise you are having. 

 

LOL regarding the amazon listing of Subaru antifreeze. List price of $77.XX per gallon, with then a huge discount. What BS. I have used Wal-Mart brand antifreeze for many years with no problems. Easy to pour in their 50 / 50 mix of antifreeze and water, instead of adding water to dilute the concentrate form of antifreeze.

 

On the top of your radiator, at the opposite end of where you add antifreeze, there is a large crew, that is removable. Remove the screw to bleed out air from your radiator. Best to have your car parked nose up on an incline, or jack up the front end to encourage the air bubble to move to the radiator, and out the bleeder hole.

 

Also, a good time to check the condition of the lower radiator hose at time of antifreeze replacement. I found my hose to be really "squishy," so thought the rubber may be breaking down internally, so replaced the hose.

[heartless]

To refill with a minimum of air left in the system:

 

Start with the front end of the car slightly elevated. ramps are great, but jack stands can work well, too. I like to have the drivers side just a tad bit higher than the passenger side...

 

1. fill the block first thru the upper radiator hose (disconnect from radiator) - when you cant get anymore into the block thru that hose, reconnect the hose to the radiator. take your time, it takes a few minutes for the coolant to work its way down & completely fill the block

 

2. open the bleed valve on the passenger side of radiator (large phillips screwdriver)

 

3. fill radiator - again, take your time, let the coolant percolate down thru all the little passages.

 

4. when the coolant level reaches the bleed valve, close it back up.

 

5. top off the radiator as needed. close cap

 

6. lower the car to the ground

 

7. fill overflow bottle to the proper level

 

8. start the car and get it to full operating temperature - drive it a few miles if you need/want to.

 

9. park, shut it down and let it completely cool - check coolant level in overflow bottle and top off as needed.

 

If you have taken your time refilling the system and gotten it filled properly, you should not need to open the radiator cap. simply keep an eye on the overflow bottle for a week or two to make sure it stays at a consistent level after driving/cooling completely for several cycles.

 

any small amounts of remaining air in the system should work themselves out and the system (if working properly) will draw in coolant from the overflow bottle as needed to replace the air - this only really works if the air pockets are small, tho.

 

weeping headgaskets may/may not be an issue - if they are bad enough, they can draw/suck air into the system. would definitely try the Subaru coolant conditioner to see if it helps.

[lvsarge]

I've used nothing but the subaru coolant and distilled water on my 06, with no problems, to help alleviate any worries about buying it.

[stackman1]

Thanks for the quick replies guys.  Yeah I saw the $77 charge too on Amazon - funny.  I use Walmart oil but might go with Amazon for my two coolant purchases.  Really surprised the Subaru Coolant is so cheap.  I am going to replace my engine oil on Sunday and get a better look at the radiator hose.  If any of you have thoughts on the following please chime in......

 

While I have been good about changing my fluids and general maintenance - I admit to not being too bold with regard to hoses.   I notice the hose clips everywhere seem rusted and the car is on getting up there in age.  Two questions:

 

1.  Any personal preferences on where to buy hoses?  

2.  Any suggestions on the best/easiest clamps to use in general - can those band clamps that tighten with a screw driver work anywhere or is there some reason to use the OEM clips?

 

Thanks

Peter

[lvsarge]

I much prefer silicone hoses to the stock rubber ones. I have them on my EJ257, but they are somewhat easy to find for that. May take some searching for your model. If not, rubbers will work, you just need to stay on top of them every couple of years to ensure they aren't cracking as part of your normal maintenance. As for clamps, I use worm clamps. Make sure to buy quality ones, harbor freight clamps are not meant for any kind of real stress. IDEAL makes nice ones, made for plumbing, but they can be pretty pricey. You generally get what you pay for in this department.

[Rooster2]

Thanks for the quick replies guys.  Yeah I saw the $77 charge too on Amazon - funny.  I use Walmart oil but might go with Amazon for my two coolant purchases.  Really surprised the Subaru Coolant is so cheap.  I am going to replace my engine oil on Sunday and get a better look at the radiator hose.  If any of you have thoughts on the following please chime in......

 

While I have been good about changing my fluids and general maintenance - I admit to not being too bold with regard to hoses.   I notice the hose clips everywhere seem rusted and the car is on getting up there in age.  Two questions:

 

1.  Any personal preferences on where to buy hoses?  

2.  Any suggestions on the best/easiest clamps to use in general - can those band clamps that tighten with a screw driver work anywhere or is there some reason to use the OEM clips?

 

Thanks

Peter

hoses from any parts store will work well. If given a choice, spend a few extra bucks, and buy more towards the top of the line in what they sell. With hoses, it is more about price, not brand name.

 

Last time I bought  bottom hose, the parts store did not have the specific molded hose to fit my Subie. They offered, and I bought a flex hose. I have found they can work very well. Usually, that type of hose is a little longer then the molded hose, but doesn't matter. It just makes for a wider hose loop, when attaching both ends.

 

I use the "air craft" type screw tighten clamps. Just don't super tighten down, or you risk cracking the plastic outlet on the radiator, that the hose slides over, or over tightening can cause the edges of the metal hose band to cut into the hose over time. Rather snug is how I tighten down.

[keith3267]

Before you buy that antifreeze on eBay, make sure it is the current Subaru LONG LIFE coolant.  If it is the older coolant with the silicates in it, then it is no bargain.  Do use the additive as well.  Peak LONG LIFE universal coolant does meet the Subaru specs.  In my opinion, any LONG LIFE universal coolant will do just as well, but it is your car and your money.  Considering that you only do this every five years, is saving a couple of bucks really worth that much to you.  Your talking about the price of a single tank of gas here.

 

Do not flush, not even with just plain water.  Ethylene glycol is very stable, but the corrosion inhibitors get used up over time.  When they are completely depleted, bad things begin to happen, and they happen fast in an aluminum engine.  The HOAT corrosion inhibitors used in modern LONG LIFE universal antifreezes can last 7 to 8 years, maybe more in some cases, but you want a margin for error so 5 years is the normal change interval.  The new Subaru coolant from the factory has an 11 year life in a new engine, but 5 years after that.

 

If you drain the radiator and block, the remaining coolant wont be much, but it will be uncontaminated.  If you flush, no mater how good you think you did, you will introduce minerals and contaminants that will attack the corrosion inhibitors in the fresh coolant and shorten their life.  It is best not to flush.

 

I have never understood the logic of removing the upper radiator hose to fill the block.  The upper radiator hose is completely open to the upper tank of the radiator so filling the radiator has exactly the same affect as removing the upper hose to fill the block.  It is a completely unnecessary step and a waste of time.

 

If your hoses are factory original, and you plan on leaving this coolant in the engine for the next 5 years, investing in new hoses, both the radiator and all the heater hoses and the overflow hose would be wise.  Just saying.

 

I would also fill the system while on ramps or jackstands, but I would warm the engine up while the front is elevated so that air could get out when the thermostat opens completely.

 

One last thing, if you buy the full strength antifreeze, be sure to dilute it with distilled water.  Bottled distilled water is only about a buck a gallon.  Be sure to check the label carefully as some distilled water today has "minerals added for taste".  You do not want this.  Premix before adding to the radiator, do not try to let the system do the mixing for you.  Make sure the mixing container is absolutely clean.  If you can't be sure, buy the premix.  The cost isn't that much greater when you consider the big picture.

 

My grandfather used to tell me that the cheapest man often ended up spending the most, and he could stretch a buck further than anyone I knew.  He just knew when to spend it to save in the long run.

[stackman1]

Wow.  Great feedback.  Had no idea silicone hoses were an option; just need to figure out diameter sizing.  Also checked out aircraft clamps - really liked the look of these worm clamps with thumb screws.  

 

http://www.brownaircraft.com/category_s/153.htm

 

http://www.autosiliconehoses.com/5mm-silicone-1-ply-radiator-heater-hose-1-metre-to-50-metres-blue-black.html

[stackman1]

Yeah Keith - I think I will just get the Subaru Conditioner from Amazon and go with the Peak Long Life Concentrate and distilled water.  The fact that the Subaru concentrate was sooo much cheaper gave me pause; it is likely as you say.  Thanks

[heartless]

I have never understood the logic of removing the upper radiator hose to  fill the block.

 

It is done that way because of the location of the thermostat on a Subaru EJ engine.

 

The upper radiator hose is completely open to the upper tank of the radiator so filling the radiator has exactly the same affect as removing the upper hose to fill the block.

 

No, it doesnt - filling the block by filling the radiator only is a bottom up proposition - and with the thermostat at the bottom of the system, the bottom up thing just doesnt work very well - unless you have hours to waste filling extremely slowly...

 

It is a completely unnecessary step and a waste of time.

 

On a Subaru EJ series engine (or any engine with a bottom thermostat), it is not a waste of time - it is actually a time saver...

[keith3267]

Are you blind?  The upper hose connects to a bung in the upper tank.  It is completely open to the upper tank.  There is no need to disconnect the hose from the tank.

 

Of course it fills from the bottom, but when the bottom is full and the coolant fills the upper tank, the coolant flows freely down the upper hose and into the heads and upper block area, just the same as if you remove the hose and poured coolant down it,

Edited February 8, 2015 by keith3267

[nicholi2789]

I am gonna have to agree with Heartless. I just recently did a timing belt job and had to drain and refill my coolant several times due to a couple complications after the fact. I filled the radiator by removing the bleeder screw then dumping coolant in until the radiator wouldn't take anymore. It did NOT flow from the radiator through the upper hose and into the block. Didn't happen. Even after starting the engine and letting it warm up with the heater on full blast it didn't fill the block. After doing that I still took the upper radiator hose off and got quite a bit of coolant down into the block. 

[dp213]

I thought the red antifreeze (asian) available at any auto parts store is the recommended type for subarus. Its about $18.00/gal and is supposed to be less harmful to the head gaskets.

[keith3267]

I'd like to know what stopped the coolant from going through that big ole hole in the top tank and down into the upper hose.  I have never seen a gate valve on that bung.  I have never had a problem filling any vehicle just through the radiator, or in the case of my Saturn, through the overflow tank.  That radiator didn't have a cap.

[johnceggleston]

 

I'd like to know what stopped the coolant from going through that big

ole hole in the top tank and down into the upper hose.  I have never

seen a gate valve on that bung.  I have never had a problem filling any

vehicle just through the radiator,

you must be new to subarus.

if you had ever owned, driven, or more on point filled the rad of a 90 - 99 subaru,

you would not be asking these questions.

 

the 00 - 04 do not have a vent plug.

but they are not as temperamental when filling either.

they relocated the top rad hose in 00.

it is now closer to the middle of the rad and higher.

(the H6 has two top hoses )

 

the filling problem in the 90s was due to the location of the hose,

and the need for the air in the block to come out the same hose the coolant was going in.

the vent plug helps in this ''2 way street'' activity.

it gives the air a short cut out of the rad.

but if you fill the coolant FAST, you will trap air in the block,

creating an air lock.

and burping may not clear it.

 

the 2 most important steps when filling a 90s cooling system,

1/ remove the vent plug

2/ fill SLOWLY

 

in the 00s the problem is not as bad.

just fill it slowly.

 

for all years,

how do you know you filled it correctly?

because it took 6 qts.

(check your manual for the exact amount, it may be slightly more.)

keep track of how much you added.

if you start with 2 full gallons, this is pretty easy,

2 qts left.

 

here's how i do it.

works every time,

no burping needed.

 

http://legacygt.com/forums/showthread.php/fill-and-burp-your-cooling-system-burpcoolingsystem-198487.html?t=198487&highlight=fill+cooling+system+siphon

 

.

Edited February 9, 2015 by johnceggleston

[keith3267]

I am new to Subaru's, I bought a new Legacy (2.5L) last year.  The radiator looks just like the radiators in all the cars that I have owned and worked on for the last 50 years.  When you fill the radiator, the coolant will fill the upper radiator hose.  I don't see any bleed valves, but I didn't look that hard either.

 

I have owned a lot of cars over the last 50 years, including some not so mainstream models, like a 1960 Borgward and a 61 Fiat Cabriolet.  I have also worked on some exotic cars owned by friends.  When I hear someone tell me that their car is unique and it takes a specialized mechanic to work on it, I find that they are simply not familiar with other cars.  There is not that much difference.

 

The biggest difference in modern cooling systems vs older ones is that most today run in reverse.  This is why the thermostat is in the lower radiator hose bung instead of the upper hose gooseneck.  (and GM uses crossflow radiators)

Edited February 9, 2015 by keith3267

[johnceggleston]

well you have lots more multi-car experience than i do.

im limited to

61 chevt pick up

67 dodge pick up

79 datsun pick up

83 isuzu diesel pick up

90 nissan pick up

and suabrus 93, 95 , 97, 98, 00, 01.

 

the simple fact of the matter is , if you fill the cooling system of a 90 - 99 legacy too fast with the vent plug closed,

you will get an air lock which is hard to get rid of.

also a fact, after market t-stats are not as large as suabru t-stats,

and will often cause overheating.

 

personally,

i'd rather re-install a 17 year old subaru t-stat than a cheap after market item.

 

but don't take my word for it,

do your own research.

i do not know everything.

but i am not alone in this statement of facts.

Edited February 13, 2015 by johnceggleston

[heartless]

Keith

 

those of us that have a few decades behind us have generally owned plenty of cars over the years, myself being another of that genre.

 

Granted, the greater majority of my car ownership, up until 2000 or so, was mostly with American name plates - Ford, Chevy & Chrysler products. When I bought my first Subaru I found that sure, a lot of my prior wrenching experience did carry over, but there was still a LOT to learn specific to these cars. I had never owned a car that had timing belts before - all previous cars had timing chains that required little to no maintenance, and if they did, it was a major undertaking.

 

the simple facts are this - the fastest & most efficient way to fill a Subaru cooling system - and almost gaurantee no issues with large air pockets - is basically the way described above. It isnt about what the radiator "looks" like, or even how it functions - it is about efficiency and making sure there are no large air pockets left in the block that can potentially cause overheating problems.

 

do a search on refilling or "burping" the Subaru cooling system here - you will find that pretty much everyone recommends the same method. Why? because it is proven to work well... heck, I learned it here! and it has worked well every time I have done it that way. (FWIW, we have had multiple Subarus here over the last 14 plus years)

 

or keep a closed mind - entirely up to you... for myself, I will continue to do it the way I described above because I know it works from experience - both from others, and my own.

[Fairtax4me]

To the OP, have you checked with an actual dealer for Subaru coolant? Last I checked it lists for about $25. And the coolant conditioner was less than $5.

 

The biggest difference in modern cooling systems vs older ones is that most today run in reverse. This is why the thermostat is in the lower radiator hose bung instead of the upper hose gooseneck.

They do not run in "reverse". Coolan still flows into the engine through the lower hose, then out into the radiator through the upper hose, just like it always has.

 

The thermostat being on the inlet side of the pump allows better temperature regulation. It keeps the coolant temp coming into the engine more consistent.

On engines with the thermostat up top you can have coolant temperature drop 50°+ in the block before the thermostat can react. Sudden changes in temperature stress the block, especially an aluminum block (which almost all modern cars have).

On the newer systems, if the temperature of the coolant entering the block is too cold, the thermostat begins to close to keep the block warm.

There is a secondary coolant circuit, called the bypass route, which runs hot coolant from the top of the engine through the heater core and delivers it back to the water pump and runs it directly to the back side of the thermostat. (The bulb side)

This secondary flow of hot coolant mixes with the cooler flow coming in from the radiator. It raises the temperature of the coolant moving across the thermostat, which helps keep it open in cold weather conditions, and maintains an even coolant temp entering the block.

 

 

The problems with filling the older Subaru cooling systems come from the upper hose and the radiator cap being on opposite sides of the radiator, and the upper hose is actually higher than the core. Once the radiator fills, the small passages in the core do not allow the air in the block to get out, thus coolant can't get in.

The same reason they put bleeders on brake calipers and cylinders. The small lines airlock and fluid can not flow in to displace the air.

 

On the older radiators they put a bleed screw on the top corner opposite of the cap, so air can be pushed out of the block and coolant can flow in. But not all of them had the bleeder, and some replacement radiators may not have the bleeder. On those cars, if there is no bleeder, you simply fill the block through the upper hose before filling the radiator.

 

On later models they redesigned the radiator. On some they run the cores vertically instead of horizontally, so the end caps are at the top and bottom. They also put the cap on the same side as the upper hose which alleviates the problem of airlock.

[keith3267]

Let me clear up a couple of things.  It is the practice of removing the upper hose at the radiator and filling it that to me is a complete waste of time.  I do not disagree with filling it slowly or having the front end elevated, many cars today require that, not just Subaru's.

 

I do not disagree about aftermarket thermostats,  That too affects a lot of cars, not just Subaru's.  

 

The cooling system does run in reverse in modern cars.  By reverse, it is the way the coolant flows through the block and heads.  It does require the thermostat to be at the water pump instead of the gooseneck like in the old days.  Coolant used to be pumped into the bottom of the block and rise up to the heads.  Engineers found out if the coolant went into the heads first and then down into the block, they could raise the compression of the engine by at least on point and increase the engines efficiency.

 

Moving the thermostat also provides better temperature regulation as noted and that too also helps the engineers bump the compression a little more as well.  I don't disagree with anyone on that point.

[upnorthguy]

  It is the practice of removing the upper hose at the radiator and filling it that to me is a complete waste of time. 

 

Please, please, let the rest of us "waste" our own time.  Well, at least the two minutes it takes to remove one hose clamp, slide a radiator hose off, and pour some coolant into the block.

[keith3267]

Knock yourself out, but you gave this advice to another person, so I will give my advice as well.

[johnceggleston]

filling the engine thru the top rad hose is a faster way to fill,

and reduces the likely hood of an air lock.

is it necessary, no.

but if you are impatient it is a way to get the job done.

i have not found any need to do it.

 

 

 

the simple facts are this - the fastest & most efficient way
to fill a Subaru cooling system - and almost gaurantee no issues with
large air pockets - is basically the way described above. It isnt about
what the radiator "looks" like, or even how it functions - it is about
efficiency and making sure there are no large air pockets left in the
block that can potentially cause overheating problems.

 one of the contributing factors to the filing issue , imho,

is how well the t-stat seal when closed.

example,

i replaced the o-ring gasket on h6 at the oil filter.

the oil filter has a coolant fill mount that the oil flows through.

i assume this is to cool the oil.

any way,

when i disconnected the coolant hose,

i had a tub prepared to catch all the coolant.

but NO.

the only coolant that drained was what was in the hose.

none flowed out of the rest of the system.

i could not believe it.

 

i'm pretty sure if i had opened the rad cap, a lot would have flowed out.

but with the rest of the system sealed,

i only got a dribble.

 

i was surprised.

[johnceggleston]

filling the engine thru the top rad hose is a faster way to fill,

and reduces the likely hood of an air lock.

is it necessary, no.

but if you are impatient it is a way to get the job done.

i have not found any need to do it.

 

 

 

the simple facts are this - the fastest & most efficient way
to fill a Subaru cooling system - and almost gaurantee no issues with
large air pockets - is basically the way described above. It isnt about
what the radiator "looks" like, or even how it functions - it is about
efficiency and making sure there are no large air pockets left in the
block that can potentially cause overheating problems.

 one of the contributing factors to the filing issue , imho,

is how well the t-stat seal when closed.

example,

i replaced the o-ring gasket on h6 at the oil filter.

the oil filter has a coolant fill mount that the oil flows through.

i assume this is to cool the oil.

any way,

when i disconnected the coolant hose,

i had a tub prepared to catch all the coolant.

but NO.

the only coolant that drained was what was in the hose.

none flowed out of the rest of the system.

i could not believe it.

 

i'm pretty sure if i had opened the rad cap, a lot would have flowed out.

but with the rest of the system sealed,

i only got a dribble.

 

i was surprised.

 

now, back to our off topic discussion.....