My life expectancy is less than 80 years.

This isn't something I'm worrying about.

 

I had the same issue...couldn't find anything other than 50/50. Drain, fill with 50/50... yes, you'll only be replacing half the coolant...so it won't be a flush, but it should be fine. Then, instead of changing every 100,00 miles, just do it every 30,000 - 50,000 miles.

If you are really worried about very old coolant...then change it a second time after driving it for a week; that'll give you about 75% fresh coolant in the system; then go to every 30,000-50,000 miles.

It's best not to mix brands/chemistry's. If you truly want to do a complete flush, then you'll have to switch brands to one that you can purchase in 100% concentration

 

Thanks for the response. I thought about doing it like you said. Flush once with the 50/50. Then do it again in a week. At this point I have 140,000 miles on it and just want to keep it running well so I'm trying to baby it. I will probably do more frequent flushes if I can't find the concentrate anywhere. Dealers don't carry it that I have found.

 

Why do you need to flush the system? Unless it got contaminated you should be fine with a drain and fill on subaru's schedule, which is 100k miles for the first one and then every 50k after that because of the residual coolant.

Alternatively, remove the 2 lowest freeze plugs on the block to drain all the residual coolant and water out. They might be single use so buy replacements first.

 

I agree. This sounds like a solution looking for a problem. I've never flushed mine. I just change it whenever I remember, or when I do the timing belt, whichever comes second. Granted, I've only had the car 23 years so it may be too soon to tell.

 

Not looking tell anyone else how to handle their car. I wanted to do a full flush, can't find what I need. So I was curious how others handle it. You don't have to do a full flush but not doing one leaves contaminants in the engine. Will it kill it? I don't know. My mother in law has smoked like a chimney her whole life and is still going. I'd rather do it once in a while.

 

Clearly the dealer doesn't do full flush but the conspiracy in my brain says... They know it shortens engine life, you buy a new car sooner.

 

Clearly the dealer doesn't do full flush but the conspiracy in my brain says...

You should see the way they do a brake fluid flush. They suck most of the fluid out of the reservoir, and replace it with new.... Never touching the stuff that remains in the lines.

 

Just thinking out loud here.... Can you use an aftermarket product or are you only willing to use something from a Subaru bottle? Autozone, for example, carries Peak "Asian Blue Coolant" in full strength concentration. It says its fine for Subarus. Now before anyone rags on me for recommending an aftermarket product, keep in mind a) I've never used this product myself, and b) there's a moderator here who rags on us if we buy Subaru-branded filters. So apparently we're wrong no matter what we do. Go figure.

 

I am running into a small issue completing a full coolant system flush. Nobody seems to carry the subaru coolant concentrate. I can only find the 50/50 mix. Doing a full flush leaves some residual water in the system. Any recommendation how to get the right coolant solution mix only using the pre diluted 50/50 subaru super coolant knowing there will be a few quarts water remaining in the block and heater core?

Just thinking out loud here.... Can you use an aftermarket product or are you only willing to use something from a Subaru bottle? Autozone, for example, carries Peak "Asian Blue Coolant" in full strength concentration. It says its fine for Subarus. Now before anyone rags on me for recommending an aftermarket product, keep in mind a) I've never used this product myself, and b) there's a moderator here who rags on us if we buy Subaru-branded filters. So apparently we're wrong no matter what we do. Go figure.

Thanks for the suggestion. I had looked into it briefly. It does keep coming up each time I look online for the Subaru concentrate. I'd have to check further. If anyone has used it I'd be curious if the see any gelling. I don't believe that the Subaru stuff is legitimately the only product that's viable. But I'm sure Subaru wants us to believe that

 

Subaru branded oil filters is actually a great idea. The oem tokyo roki filters will always have the correct filter mesh and bypass valve pressure. A bankrupt company with outsourced mfg might not be as diligent.

I have used the peak coolant on an accord that leaked at the thermostat and water pump. Seems fine and it worked well for years even at subzero temps. But no one can guarantee whether or not it will react with the residual subaru coolant. For the small price difference, I wouldn't bother.

Residual coolant shortens service life if the old stuff has gone bad. If you change it on time it's fine.

 

My Subaru dealer tells me that they only offer their "Super Coolant" in the 50/50 mix and that the "Long Life Coolant" is no longer available.

You can either flush it with 50/50 and waste coolant, or do what Buzzw suggests and drain/refill at frequent intervals.

Unless the system has been neglected, the latter approach makes more sense to me.

I agree that mixing coolant types, or even brands, can be risky.

 

I am running into a small issue completing a full coolant system flush. Nobody seems to carry the subaru coolant concentrate. I can only find the 50/50 mix. Doing a full flush leaves some residual water in the system. Any recommendation how to get the right coolant solution mix only using the pre diluted 50/50 subaru super coolant knowing there will be a few quarts water remaining in the block and heater core?

My Subaru dealer tells me that they only offer their "Super Coolant" in the 50/50 mix and that the "Long Life Coolant" is no longer available.

You can either flush it with 50/50 and waste coolant, or do what Buzzw suggests and drain/refill at frequent intervals.

Unless the system has been neglected, the latter approach makes more sense to me.

I agree that mixing coolant types, or even brands, can be risky.

See my other response above. I have the Subaru 50/50 ready to go. I don't want to mess with mixing and draining the blocks and heater core are more work than I have time for at the moment.

 

Yeah I have landed on more frequent flushes. My car has had regular maintenance since I owned it. Just trying to do more of it myself now. Tired of finding things that the shops do to my car and don't bother to inform me about. Stripped lugs, broken fasteners on my engine cover, etc. I'd rather take the time do do it myself so I know what is actually being done.

 

Did the flush today. I managed to get 7qt out by draining both radiator and the lower hose on the driver side. I'll just be doing more frequent flushes.

 

Cool. BTW, subaru has the shop repair manuals and Technical Service Bulletins available on their website. I recommend you purchase a 3-day subscription and download as much as you can for future reference. https://techinfo.subaru.com/stis/ I too, have started doing a lot of my own maintenance. I'm a perfectionist...and a few things have aggravated me. I'm sharing them with you so you don't get aggravated when you read the OEM manual and run into hurdles. Here's a few: When replacing the coolant, Subaru says you must add a "conditioner" ... it turns out that the local dealerships don't stock it (so how the heck do they add it when they do a coolant "flush"?); turns out it is basically a stop-leak because of problems they had decades ago with gaskets...but the problem is solved and therefore the dealers don't stock this product. Also, when changing certain parts or fluids, Subaru Shop Manual states to use a new locknut or a new washer...yet the local dealerships don't stock those locknuts or washers (I can't rememeber exatly...Transmission fluid drain/fill washer or differential washers)....so I infer that they don't follow the OEM service manual and just re-use the hardware. Also, you won't find the right subaru branded manual transmission fluid in quart nor gallon containers, well, not even 5-gallon containers at the local dealership...so that tells me they use another brand and they've been having good success (By the way, I was able to order a 5-gallon can of the transmission fluid (Subaru Gear Oil Extra MT)....it wasn't in stock, I did a web order ... shipped to local dealership ... it was expensive; but my son has a Subaru too, and I figure this'll get us both through a couple of fluid changes over the next 3 years).

I'm happy to hear that you've decided to do more of your own maintenance. I applaud you. Cheers.

 

Cool. BTW, subaru has the shop repair manuals and Technical Service Bulletins available on their website. I recommend you purchase a 3-day subscription and download as much as you can for future reference. [URL=https://techinfo.subaru.com/stis/]https://techinfo.subaru.com/stis/[/URL][/URL] I too, have started doing a lot of my own maintenance. I'm a perfectionist...and a few things have aggravated me. I'm sharing them with you so you don't get aggravated when you read the OEM manual and run into hurdles. Here's a few: When replacing the coolant, Subaru says you must add a "conditioner" ... it turns out that the local dealerships don't stock it (so how the heck do they add it when they do a coolant "flush"?); turns out it is basically a stop-leak because of problems they had decades ago with gaskets...but the problem is solved and therefore the dealers don't stock this product. Also, when changing certain parts or fluids, Subaru Shop Manual states to use a new locknut or a new washer...yet the local dealerships don't stock those locknuts or washers (I can't rememeber exatly...Transmission fluid drain/fill washer or differential washers)....so I infer that they don't follow the OEM service manual and just re-use the hardware. Also, you won't find the right subaru branded manual transmission fluid in quart nor gallon containers, well, not even 5-gallon containers at the local dealership...so that tells me they use another brand and they've been having good success (By the way, I was able to order a 5-gallon can of the transmission fluid (Subaru Gear Oil Extra MT)....it wasn't in stock, I did a web order ... shipped to local dealership ... it was expensive; but my son has a Subaru too, and I figure this'll get us both through a couple of fluid changes over the next 3 years).

I'm happy to hear that you've decided to do more of your own maintenance. I applaud you. Cheers.

I really appreciate the knowledge buzz. I had already reached out to the local shop and asked them if the conditioner is recommended. I have found online that it can cause problems with newer generation engines due to clogging. As you pointed out, the new generation engines resolved the leak issue so there is no sense in using the conditioner. Would you be at all surprised when I tell you, the local shop never called me back about my question on the conditioner. So I didn't use it.

I also tried to get a new radiator drain plug washer. Found the same issue as you, dealer doesn't carry it. I ordered one from an auto part supplier,but it's only carried with a drain plug in combinationand. it was close in size however it was not identical. The new washer immediately leaked with just residual fluid in the radiator. So I put in the old one (which looked in good condition anyway) and it worked without issue.

I also want to get to my trans fluid, but brake bleed is next.

Fyi, I also am a perfectionist. In my case it's in part a function of diagnosed OCD.

 

It's a small bottle of viscous fluid.