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Guest Message by DevFuse

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Split Radiator

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19 replies to this topic

#1 Guest_glwagturbo_*

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Posted 21 March 2003 - 06:37 AM

I have 90 legacy that just developed a crack/split in the plastic side tank of the radiator. Are these easily repaired or do you recommend just getting a new rad?
If so, any one know of a reputable rad guy in LI NY.



#2 Guest_gotsubarus_*

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Posted 21 March 2003 - 07:31 AM

Get a new one... Is the crack on the passenger side front?

Get a new one and instal it yourself. I get new Modine copper for 125.00. Also replace the thermostat with OEM from Subaru, easy to instal.

#3 Guest_glwagturbo_*

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Posted 21 March 2003 - 12:06 PM

Great thanks

Yes its the passenger , yes right side.
I just got a quote of $120 also. I plan to change the whole thing myself. It has 135k. I guess I would be stupid not to.


#4 Guest_pmonro_*

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Posted 21 March 2003 - 01:15 PM

Failure of the end cap is not unusual. It usually appears as a 3 inch split in the flat surface near the top on the side the hot water enters ie passenger side for USA
The original radiator had a aluminium core and most of the rest of the water circuit is aluminium. No doubt there are a few other(non aluminium) metals.
Now you are going to put in a big piece of copper. Consequently a lot more corrosion could be expected.
For a vehicle that is only a few years old I would recommend retaining the alumimium radiator by replacing the end cap. However in an older vehicle it may be more cost effective to replace it with a copper radiator

#5 Guest_Legacy777_*

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Posted 21 March 2003 - 01:57 PM

I'll be damn........this could be a similar issue..........very interesting.

Can you get an aftermarket aluminum radiator?

Pros/cons of copper over aluminum......other then corrosion and such?

#6 Guest_pmonro_*

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Posted 21 March 2003 - 10:43 PM

Hi Josh
Copper radiators are much cheaper than Aluminium by a factor of 2 or 3. I understand they are still available in the USA because about 4 months ago a Florida resident had a similar posting in this board and I think I remember he had a quote for an aluminium radiator.
When mine split I was given the option of a copper radiator but I have had previous experience with corrosion in water circuits that use copper and aluminium and the corrosion can be high. One really needs to keep the inhibitors in top condition.
The thermostat is also questionable since it is usually made of brass. Is the Subra also brass? In one vehicle I had (not a subaru) a hole punched through 1/8 aluminium in just a few years which I attributed to the brass regulator.
On a good vehicle I would replace the end cap. Unfortunately this costs nearly the price of a new copper radiator. However our Florida resident could not find anyone to do it. Perhaps the supply of end caps has dried up.

#7 Guest_Legacy777_*

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Posted 21 March 2003 - 10:52 PM

Thanks for the info pmonro.

I've got a coolant system pressure tester.....it looks like it's for the larger, domestic radiator cap......not sure if it has an adapter, or if I can rig it so I can tell where the leak is coming from.

So is copper going to corrode much faster? or the combo of the two metals.

I'm not sure if the center portion of the t-stat is brass or not. I know the outer cage is aluminum or SS.

Is there a trick to doing the end cap? or can I just bend all the tabs back and do it myself?

#8 Guest_pmonro_*

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Posted 22 March 2003 - 01:42 PM

Hi Josh
Glad to be of some help
The aluminium will corrode.
If you say the thermostat outer case is aluminium there is added evidence to suspect that the subaru design phylosophy has probably been to provide a full aluminium circuit so as to minimise corrosion. Strangely however the temperature sensor is brass
Stainless steel is probabbly the next best material to minimise corrosion in an aluminium circuit. So I suspect the water pump impellor is aluminium and the shaft possibly 303 stainless. The correct pH for aluminium and stainless water circuit is 6. ie slightly acid. I guess that is not much use unless you can measure it.
It is common also to have to replace a copper radiator after say 6 to 10 years because they rot. However the aluminium radiators seem to hang on for much longer.
I can not help with info on replacing the end cap. Forty years ago I would have done it myself but now I just fork out the cash. It can not be too hard. I took the car to a "one man band" radiator specialist. He did not seem overconfident with the replacement to indicate he had any special equipment.

#9 Guest_Legacy777_*

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Posted 22 March 2003 - 08:44 PM

Well I rented a pressure tester from autozone.......it was a POS......didn't fit. Ended up borrowing one from a mechanic down the road......great guy.

Well, you were right......it's the end cap on the passenger side, near the top, it's on the portion that's facing the front of the car.

There's a place locally here in town that my mechanic buddy recommended. So I'm going to give them a call on monday. Hopefully they can get it for me relatively soon.....It'd be nice to get it in before next saturday when I have to take it to the body shop....again for them to fix their mess up.

Wonder why it splits right at that spot.......hmmm

#10 Guest_james hogan_*

Guest_james hogan_*
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Posted 23 March 2003 - 12:15 PM

Replaced my radiator @ 153K on a 90 Leg. Split on top front, pass side. Good thing I had a parts car.

Knowledge is power. I bought the parts car for the rebuilt tranny. now I'm just waiting for it to let go.

My 2 cents.


#11 Guest_glwagturbo_*

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Posted 24 March 2003 - 06:52 AM

I picked up the copper Rad. for 120+ tax and it took about 3 hours to do. Most of the bolts holding the fans on snapped. I had to Buy some replacements. 6mm. Otherwise it was not to bad. The lower ( original) rad hose was a pain to get to. i cut and replaced it also. It was an automatic, so the lower tranny line was a little hard to pull off. Overall not too bad.


#12 Guest_Legacy777_*

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Posted 24 March 2003 - 08:31 PM

Hey pmonro,

I found a copper radiator for 115 + tax. So I'm going to do that....should have it tomorrow, and will pickup a new t-stat as well.

This copper one has a lifetime warranty too......go figure.......

#13 Guest_pmonro_*

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Posted 25 March 2003 - 05:43 PM

HI Josh
I see you have decided to use a copper radiator. .
However the theoretical figures can be obtained from reference to the Electrochemical Series voltages.
If there are no disimilar metals as I suspect is the situation in the original legacy then there is no electrode potential to cause electrolytic corrosion.
In the cars that have iron engines and copper radiators (for comparrison) the potential is 0.8 volts.
With aluminium engines and copper radiators the potential is 1.7 volts. Hence my concern about the use of a copper radiator
In each installation the copper is protected from corrosion by the engine material. The copper rots from external sources possibly road salt or whatever.
I can not say with any certainty how this will go because I have the aluminium one. It would be of interest to hear from those who have had the copper radiator for say 5 years or more.
I suspect you have chosen the copper radiator because of its low cost.

#14 Guest_Legacy777_*

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Posted 25 March 2003 - 06:14 PM

I don't quite get what you mean about the potentials.....do you want a higher potential or lower potential?

I'm mainly concerned about the cooling capability of the copper one over the aluminum one, and how it's going to affect the rest of the system.

If you don't mind, can you shoot me an email. I'd like to discuss some of the pros/cons of doing this. I'm starting to think I should have gone for the aluminum one.......

Like I said....this one has a lifetime warranty.......I'm goin to do some snoopin on google and see what I can turn up.

I may try ezboard's new PM feature and see if I can get a hold of you that way.

#15 Guest_pmonro_*

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Posted 25 March 2003 - 09:26 PM

There are several web sites that list the electrochemical series and how they predict corrosion.
The combined effects can be calculated by adding the potentials for each metal.
They can be found using goole search with the exact words "electrochemical series"
The lower the combined number then the lower the prospect for electolytic corrosion.

#16 Guest_glwagturbo_*

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Posted 26 March 2003 - 06:23 AM

Your points is welly taken. I never considered that when I change the rad. in my weife legacy last week. Actually, the rad shop did not even give me a choice. I was surprised to see a copper one, but just asked him if it was a drop in replacement.
Maybe some one will chime in who has had a replacement over 5 years.
We used to have a similar problem trying to get SS hub covers off an aluminum wheel.


#17 Guest_Legacy777_*

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Posted 26 March 2003 - 08:44 PM

Well....update.......after doing some more research and talking with Peter and a couple other people.......I've decided to get an aluminum radiator to keep things "meshing" well.

edit: autoparts store on the net shipped me a copper/brass radiator.....it's not aluminum.....despite the fact they told me it was. To their credit, they are fully refunding my money, and paying for shipping back to them.

edit2: Did some more searching, found a very knowledgable and extremely helpful place.

The name is Trans Pac Motor Parts. You can call them at 1-800-922-1983. Don is the one who helped me. Extremely nice/helpful guy.

Here's their page tpmpinc.com/

The aluminum radiator ran me $175, which isn't bad. Brand is koyo.

#18 Guest_99obw_*

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Posted 26 March 2003 - 08:58 PM

Nice find!

#19 Guest_Legacy777_*

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Posted 28 March 2003 - 03:33 PM

here are some discusions with more technical info that I have had. I will archive this in a few days probably, unless it sparks more interest.

<span style="color:red;">>>>></span>

<span style="color:blue;">I'm in a major debate on what to get......and the main issues I'm coming down to is what is going to happen over time when I mix a copper/brass radiator with a previously all aluminum cooling system. What about the electrolysis or other issues like that between the two metals?

Any comments/suggestions?

Thanks </span>

<span style="color:red;">>>>></span>

Josh, you hit it on the head... the galvanic reaction between brass and aluminum generally yeilds corrosion, big time, (I work in a brass instrument factory where we experiment with this all the time).

One of the guys at the shop has a 96 BMW, and runs BMW coolant and de-ionized water in his all-aluminum cooling system. His radiator is like new, and I mean NEW, inside. I'm gonna do that in both my cars.


<span style="color:red;">>>>></span>

<span style="color:blue;">Well.....I've done some more snooping.....can't get replacement end caps....the cost of a new radiator is around $320 (aluminum) $115 (copper/brass).

I've talked with several shops, as well as one of our corrosion techs here at work, and they said I should be fine as long as I maintain the coolant changes on a regular basis.

Dean I value your opinion and background, and am just curious what sort of testing do you do on the dis-similar metals, etc?

I just don't know if I want to spend an aditional $200 on an OEM one when so many people have used the copper/brass radiators and haven't had any problems.

Josh (confused and unsure which way I will go...) </span>

<span style="color:red;">>>>></span>

Hey Josh,
I work in a custom trombone factory where we make valve trombones (and everybody there is a car nut, too). For years our metallurgist has tried to get brass and aluminum to work, but we've had no sucess yet due to pitting from severe corrosion. We've tried all different anodization processes and coatings, even ones that are known to be non-porous. They all end up looking like most radiators, and this is just from the g reaction, no human Ph was introduced.

A few months ago, a guy at work was changing his coolant on his newly aquired 96 525i. When he drained it, we got a good look in the radiator with a bore scope. It was IMMACULATE!!! He drained what the previous owner told him was the original coolant... (the previous lady owner did virtually nothing to this car). This radiator looked brand spankin' new inside. After seeing that, there's no question in my mind which way to go here, especially if you want to keep the car for a long time.

Brass radiators work less and less efficiently the second this reaction starts, but you could still get years of service from a one if you use a decent coolant and flush it once a year. Check out a BMW radiator before you buy the cheap-ee, if possible.


<span style="color:red;">>>>></span>

<span style="color:blue;">Again Dean,

Thanks for all the good info. What exactly is this "g reaction" Is that just from putting the copper & brass together? Or what causes the reaction?

Not sure if you got my other post saying I was going to get the aluminum one. Yes it is cheaper then a subaru one.....and may not be as high quality....don't know.....but I'm satisfied with the fact that I'll be sticking with aluminum all throughout the system.

I'm sure the BMW one is a good unit.....but I don't want to spend the money that it most likely costs, nor do I want to custom fab something to make it fit. I'll just use the aluminum OEM replacement.


<span style="color:red;">>>>></span>

<span style="color:green;">Hi guys,

I am curious about this debate - In the trombone factory - aren't the metals being physically joined together? This would definitely cause the anode/cathode affect, but if they are just in the same system connected by coolant, will it have any effect since the fresh coolant is loaded with anti-oxidants?

I have a brass copper 2-row rad the absolutely rocks on the stock spec Aluminum rad for half the cost. Sure it's bigger - but stock rads don't cut it. It isn't a Legacy, but it's a pretty damn fast Turbo GL-10 Wagon. The turbo EA82T's are infamous for heating issues, and this was solved by getting a larger aftermarket 2-row copper/brass rad - that can be fixed at any rad shop by the way. This nicely protects the freshly rebuilt motor from any overheating threats.

Personally I'd go for a larger custom copper brass rad for half the cost.

The debate continues....</span>

<span style="color:red;">>>>></span>

These experimental aluminum valves we're trying in our trombones have a top and bottom bearing that do make light contact with the casing through a very light oil. So , yes, you're correct. Oddly, though, when left to sit untouched for several days, the corrosion starts on the non-contact areas of the valve, (through the anodized section) not the worn (bare aluminum) bearing surfaces. Eventually corrosion makes its way to the bearings and causes it to fail permanently.

The metalurgist at our shop today reinforced using de-ionized water and a good grade (not Prestone) of coolant which he says should work fine in a normal cooling system. But he also said (under his breath) "or just stick to an all aluminum system, like in my BMW" (sort of touting his intelligent choice of cars... I hate that!). However, after seeing the inside of his cooling system and seeing what the proper mixture of 5 year Prestone has done to my radiator, I still have to say that an all-aluminum system is the way to go, if you want the best for your car that is.

comments, suggestions,


<span style="color:red;">>>>></span>

<span style="color:blue;">So he is or is not saying prestone is a good coolant?

I have it....and haven't had any issues with it.


<span style="color:red;">>>>></span>

Hey Josh,
He says he doesn't believe Prestone provides sufficient protection to prevent the reaction from starting,( if it's going to start), especially when used with regular tap water. My guess is that it may have to do with how hard the water is and the ability of the Prestone to neutralize the reaction (but I'm certainly no chemist).

Currently, I have 5 year Prestone anti freeze and tap water in my 3 year old Fiesta's radiator. Although the engine is iron, the H2O pump, cross flow pipe, and T-stat housing are aluminum. A galvanic reaction has definitely started in the system and the aluminum parts are corroding. Everything still functions okay, but once again, you gotta see this BWM cooling system.... FRIGGEN SPOTLESS!!!

De-ionized water is cheap and plentiful. Maybe it's worth it to mix it with Prestone for your soon-to-be all-aluminum system????


<span style="color:red;">>>>></span>

<span style="">yeah.....I was goin to probably pick some up......is de-ionized water the same as distilled water.....or is there a difference? Which would be better?


<span style="color:red;">>>>></span>

I think de-ionized H2O is electrically discharged (electron "free"?) and distilled isn't. But hey, I just build trombones and fix guitars for a livin'...

Maybe someone out there knows????


#20 Guest_Legacy777_*

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Posted 29 March 2003 - 08:23 PM

Here's another one with peter and I.

Hi Josh
About a copper radiator
Well as you see from our postings I am a bit wary of using a copper radiator.

Not that I believe that there will be any difference at all in the cooling effect.

Just because the subaru was supplied with an aluminium one and there is every
reason to believe that a copper one will corrode the aluminium circuit.
In a motor that has only a few years life, this is no problem and the low cost
is attractive. However if the life expectancy is more than say 2 years I would
have a good think about it.
Again, If copper had been suitable then why was it not supplied with the original
The Electrochemical series lists the potentials for metal corrosion. You can
find these on the web with an explanation using google search. This is the theoretical
approach but in practice other factors may be significant. IE use of inhibitors.

However the numbers indicate the probability of corrosion.
The numbers I gave on the subaru site are the combination numbers for the mixture
of materials. The lower the number the lower the prospect for corrosion.
As for the life of the copper radiator and its lifetime guarantee, This refers
probably to the life of the car. However a radiator purchased for a second hand
car would not be expected to last more than say 7 years because a car would
probably be at least 7 years old before it required a new radiator and therfore
it life would then be 14 years (I have not put that very well but I think you
can get what I mean)
Fire as many questions as you like. I hope I can answer them.

<span style="color:red;">>>>></span>

<span style="color:blue;">Hey Peter,

Thanks for the email. I'm beginning to think that aluminum would be best to stay with.

I've done a little bit of research on things, and what I can tell some of the factors between the two are weight, size, heat transfer capabilities......and so on. For the most part all those aspects are physical traits. Weight is more with a copper radiator....but oh well. Cooling capacity between the two are similar.

However I haven't found much info on the chemical properties of mixing copper and aluminum.....and switching from one or the other. I just don't know what to do. I don't want things corroding in my engine. I'll pay more now to keep things working properly, rather then have it screw up my engine.

I've emailed www.narsa.org after reading this article www.narsa.org/press/releases/980201.htm

I've asked them for the name of shops in my area that could do the end cap replacement, and if they have any comments on swapping radiator types.

I picked up the copper radiator today....it's sitting in my living room. Like I said....I still don't know what I'm going to do.....but hopefully I can get a response back from narsa, and if I can find a place here that will replace the end caps for a reasonable amount (under $100) I think I will go that route in order to keep everything in the cooling system aluminum.

So....any comments or suggestions you want to give me....I'm all ears. I'm probably going to call one of the corrosion techs at the office I used to work at. I work for a natural gas pipeline company, and we have cathodic protection on all our lines. So hopefully one of the corrosion techs/engineers can give me some info on some of the possible chemical/electrolysis issues.


Josh </span>

<span style="color:red;">>>>></span>

I understand how you feel. It is exactly why I decided to stick with the aluminium
radiator when I was faced with the situation some years ago. I was just not
prepared to take the risk. However at that time my vehicle was only about 5
years old so the decision was quite simple.
The only problem I had was that there was no guarnatee with the repair whereas
the new radiator had a guarantee of some sort. Apart from that I was prepared
to take the risk on the repair against the risk of the possible consequence
of having a non standard component.
>From the contrary argument it could be argued that there are heaps of vehicles
with aluminium in the circuit and copper radiators. However I have a subaru
and I am not sure that is relevant.
It would be good to hear from someone who has had a copper radiator for say
5 years. The trouble is that probably not many have had them in that long and
just one or two responses is not significant.
I can understand you not wanting to buy a new aluminium radiator because of
price. Did you get a quote. From memory I was quoted US$400.
Are you having difficulty finding someone to replace the end cap or is the cap
not available?
For $100 I would replace the cap and spend the next two years sleeping well
at night!!!
I read your reference link. It will be interesting to hear what others say.

Send as many questions as you like.

<span style="color:red;">>>>></span>

Just another idea
Do you have a subaru dealer. Ring their maintenace workshop and ask them what
they can do. It is likely they will offer to replace the radiator with a new
one, but if they offer to replace the end cap then it is possible there is a
firm in your locality that does this. Most dealers use specialist firms for
I do not know how things are in your area but here in Auckland we have small
business that specialise in radiator repairs. They do all makes and models and
our dealer will send his radiator repairs to them and add a percentage.

<span style="color:red;">>>>></span>

<span style="color:blue;">Hey Peter,

Well I've done some more snooping, and they don't have any end caps for my model radiator. So it's either new aluminum radiator at $300+ or keep the copper/brass one with lifetime warranty that cost $115.

I've talked to several more people and they've all said that I shouldn't have any issues as long as I maintain the cooling system. I also talked with one of our corrosion techs, and he said it should fine. He did say if it was steel and copper/brass then that would be a problem.

I don't know if I can justify spending the extra money when I've been told by people that work in the business and know their stuff that say it will work fine.

I may sit on it for another day or so.....have to wait and see.


<span style="color:red;">>>>></span>

I wondered if there was a shortage of end caps. Probably they have all been
used up and no more are being produced. This indicates to me that the radiators
have been repaired in preference to being replaced.
So you really are running short of options. At this stage you have no alternative.

As I have previously said I have no experience with a copper radiator in this
car so if you have no other alternative then that is all you can do.
Perhaps it will be fine. I can not comment except to agree with your expert
that the inhibitors would need to be maintained.
Just another idea. The drivers side end cap does not seem to fail. I wonder
if is the same as the passenger side. You could swap it from a demolition radiator.
I am "clutching at straws now"

<span style="color:red;">>>>></span>

<span style="color:blue;">Well.....guess what!!

Someone suggested I do a search on the net. I found a place in california that sells wholesale car parts. They had OEM spec aluminum radiators with the plastic end caps for $126 shipped!! They even listed the subaru part number. So I went ahead and ordered one....will be here next week some time. I'm going to take the copper/brass one back tomorrow.

You know....this is the second time I've done this.....buy a new part locally.....and end up finding a better deal or better part elsewhere. Houston just sucks.......haha.

I feel a lot better putting an aluminum radiator back in. I will have to pick up some distilled water too. One guy mentioned something too about de-ionized water......any benefit to running this, or where to even get some?

Thanks for all your help.


<span style="color:red;">>>>></span>

Yea you have got it.
I think you would regret using the copper one.
I remember I once had a toyota with a copper radiator where I had to replace
the head gasket every two years because of corrosion under the aluminium head.
It sure happens. That is why I am sticking to my aluminium radiator to the end.

Your OEM aluminium radiator may not be as good as the subaru original but it
is a much better bet than a copper one.
You should put your solution on the subaru site. There are a lot of guys who
do not even know that the radiator is aluminium and even more who do not realise
the significance of replacing it with copper.
This problem is going to get worse with the legacy as they get older.
I sure like the price of your aluminium radiator. I wonder if they are available
here. It pays to keep a look out for things that may be needed in the future.

So now you will sleep better at night with the knowledge that you have kept
the vehicle as straight as possible.

<span style="color:red;">>>>></span>

I realise I did not fully reply to your questions about water.
Electrolytic corrosion occurs when material dissolves into the water and is
transported in it and deposited at another place. It can occur in very pure
water but at a much slower rate than in a salt solution. So the idea is to keep
the dissolved salts as low as possible.
Now distilled water meets this requirement. I am unsure if de-ionised water
is any better.
By selecting an aluminium radiator you have greatly reduced the prospect for
corrosion. These other factors are of lesser importance.
Practically few people use distilled water. Tap water is most common. However
tap water varies in composition from place to place.
Distributors of water usually add lime to it to bring its pH into the alkaline
region. They do this to reduce corrosion to their concrete pipes.
However low aluminium corrosion is best achieved when the pH is about 6 (ie
slightly acid)
Also tap water may have many dissolved salts.
I use rain water because we live in a rural area and collect the water for house
use. It has a pH of less than 6 and I expect is low in dissolved salts.
You could get an analysis of your tap water from the water Utility however it
might not be very helpful. You would need to know what level of salt content
was acceptable for low corrosion.
I wonder what the dissolved salt content in your bottled water is like. I imagine
it is quite low but sometimes salts are beneficial beacuse they give a nice
taste to the water.

<span style="color:red;">>>>></span>

<span style="color:blue;">Thanks for the feedback Peter.

Yeah, I know the "OEM" one may not be as good as subaru one, but it's probably not going to make much difference. I just didn't want to put that copper/brass one in. Just didn't have a good feeling about things.

Again thanks for the schooling on the water. I can get distilled water pretty easily, so I'm just going to do that.

I have normally just put tap water in.....didn't really think it would be a big deal. The tap water here is pretty minerally.....no idea about salt content though.

I'm sure everything will be fine.


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