Coolant leak, but where?

[mrfixiter]

Hi there.

1997 Legacy, MT, GT Wagon with 172k miles. I checked under the hood the other day and saw the coolant recovery tank was nearly empty. I borrowed a radiator pressure tester from the local Autozone store and it's not holding any pressure. When I pump up the tester to about 5 lbs, I can hear air coming out from somewhere around the coolant bleeder screw and the upper radiator hose where it attaches to the radiator. I don't see any visible cracks or damage to any of the components. I replaced the  hose but the problem still exists. When the engine was running you could see coolant dripping around where the radiator connects to the hose. I torqued down the hose clamps to 35 in-lbs and made sure the bleeder screw was tight. I'm not sure what other adjustments or tests I can make. Do I need to refill the radiator to the top for the pressure test to be accurate? Presently, the coolant level is about an inch or two below full.

Edit: I wonder if putting some soapy water around the place where I hear the air will pinpoint the problem?

Thanks for your reply.

Edited April 17, 2021 by mrfixiter
Afterthought.

[jonathan909]

Sure, the "snoop" thing should work.  But what's wrong with just refilling it, running it up to temperature, and looking for the spray?

[moosens]

Does that radiator have the square head plug atop the unit on the right side ? 
 

Just this past week I saw a leak but it was so small I couldn’t locate it. Same area you mention and it’s a 2.2

I did the $3.79 bottle of radiator leak stop. It worked for now. I have a new radiator on standby but when I went to do the repair I couldn’t get it to leak or overheat. I never recommend the easy bottle “fix” but this was so minute maybe this was the right time to use it. 

When I fill those style I mentioned above I follow directions given to me by the folks who work on them all the time. Take the square head plug out and fill while running until there’s no more air in the system then of course put the plug back in. From there you should be able to consider your coolant system topped off. 
 

 

[mrfixiter]

17 minutes ago, jonathan909 said:

Sure, the "snoop" thing should work.  But what's wrong with just refilling it, running it up to temperature, and looking for the spray?

I was trying to avoid making a mess with the spillage but that certainly sounds like the most direct method. I'll check it out if the soap bubble test doesn't get me anywhere.

16 minutes ago, moosens said:

Does that radiator have the square head plug atop the unit on the right side ? 
 

Just this past week I saw a leak but it was so small I couldn’t locate it. Same area you mention and it’s a 2.2

I did the $3.79 bottle of radiator leak stop. It worked for now. I have a new radiator on standby but when I went to do the repair I couldn’t get it to leak or overheat. I never recommend the easy bottle “fix” but this was so minute maybe this was the right time to use it. 

When I fill those style I mentioned above I follow directions given to me by the folks who work on them all the time. Take the square head plug out and fill while running until there’s no more air in the system then of course put the plug back in. From there you should be able to consider your coolant system topped off. 
 

The square headed bleeder plug sits atop the radiator on the passenger side which is the left side when you're standing in front of the car looking under the hood. I put pipe thread tape on it but that didn't help. I've heard so many bad things about using a stop leak additive whether it be for radiators, tires, A/C systems, or motor oil. I'd rather just fix it properly.

Thanks for your replies.

[jonathan909]

Clarification:  The stuff in question is Subaru's "Cooling System Conditioner" - it comes in a little blue jug for a few bucks, as mentioned.  It's highly regarded around here (within reasonable limits, of course), won't do any harm, and may well seal up a very small leak like this one.  Absolutely worth trying.

[mrfixiter]

20 minutes ago, jonathan909 said:

Clarification:  The stuff in question is Subaru's "Cooling System Conditioner" - it comes in a little blue jug for a few bucks, as mentioned.  It's highly regarded around here (within reasonable limits, of course), won't do any harm, and may well seal up a very small leak like this one.  Absolutely worth trying.

Thanks for the suggestion. I'll check it out.

[lmdew]

Plastic tank to aluminum radiator core gaskets often leak a little.

The vent plug has a rubber gasket on it, it's all that needed.  Don't over tighten it!

[mrfixiter]

8 hours ago, lmdew said:

Plastic tank to aluminum radiator core gaskets often leak a little.

The vent plug has a rubber gasket on it, it's all that needed.  Don't over tighten it!

The radiator core gaskets aren't replaceable items, are they?

Regarding the vent plug, is that the same plug that I was referring to as the coolant bleeding screw near the upper radiator hose?

Thanks for your reply.

Edited April 17, 2021 by mrfixiter

[heartless]

if it is leaking at the seam where the plastic cap meets metal radiator core, then you are looking at a radiator replacement, not a "fix".

[mrfixiter]

2 minutes ago, heartless said:

if it is leaking at the seam where the plastic cap meets metal radiator core, then you are looking at a radiator replacement, not a "fix".

Just to clarify, is that the plastic cap which I'm calling the coolant bleeding screw? If not, where is this plastic cap?

Thanks for your reply.

[moosens]

That’s the right side of the car. Never mind looking at it from any other angle. When describing issues and locations you should refer to it as you drive it. You don’t turn left if you turn towards the radiator bleeder screw.

You say you want to do it right then get a radiator and new hoses. 
 

You won’t be able to service your existing radiator. 

[mrfixiter]

Quote

That’s the right side of the car. Never mind looking at it from any other angle.

From now on, I'll use left and right as is standard in the automotive industry.

Any suggestions as to where I can get the best deal on an OEM replacement radiator from a reputable online dealer?

Thanks for your reply.

[1 Lucky Texan]

others may have better, more extensive suggestions, but finding a Denso or Koyo radiator would be good. If a local parts house can't get you one, try RockAuto or Amazon, etc.

[jonathan909]

Once again, the wrecker is my first stop - if I get a leaky one, they warranty it.  But that's a matter of proximity and convenience - YMMV.

On the left/right thing:  My argument would be for adopting "port" and "starboard" - terms that exist to eliminate the which-way-are-you-facing problem.

[mrfixiter]

29 minutes ago, 1 Lucky Texan said:

others may have better, more extensive suggestions, but finding a Denso or Koyo radiator would be good. If a local parts house can't get you one, try RockAuto or Amazon, etc.

I looked at RockAuto. Looks like they have some amazing deals there!

24 minutes ago, jonathan909 said:

Once again, the wrecker is my first stop - if I get a leaky one, they warranty it.  But that's a matter of proximity and convenience - YMMV.

On the left/right thing:  My argument would be for adopting "port" and "starboard" - terms that exist to eliminate the which-way-are-you-facing problem.

Convenience being the keyword here. I do like your suggestion of using "port" and "starboard."

Thanks for your replies.

[mrfixiter]

Hi everyone

I really appreciate all the suggestions you've put forth. The one post that sealed (no pun intended!) the deal was the suggestion to fill up the radiator and then run it up to temperature. I didn't follow that route exactly but what I did do achieved the same result. I filled up the radiator and then I used the pressure tool again to see what would happen. As the pressure rose to about 6 psi, a tiny stream of coolant started streaming down from the top of the radiator, several inches away from the bleeder screw. I will be ordering a new radiator.

Thanks again for all your replies.

[mrfixiter]

Hi

I went to the RockAuto webpage, entered the year, make, model, and engine size. Conspicuously absent were the queries for  body style (GT wagon) and transmission (M/T). These are the choices that came up.

I clicked on the info button for a few of the radiators and some of them mention oil or transmission lines. For example, the KOYORAD radiator says:

Quote

Internal Transmission Oil Cooler?	Yes
Outlet Diameter (IN)	1.5
Tank Material	Plastic
Transmission Oil Cooler Diameter	0.875
Transmission Oil Cooler Included?	Yes

 

Does it matter if a buy a radiator that has the oil coolant tubes even though I won't be using them? The KOYORAD website says there are no radiators available for my car (where I did have to enter body style and transmission type).

When I did a another search by typing in the Subaru part number directly which is, 45199AC100, then I got a completely different list of radiators.

RockAuto doesn't seem to offer any tech support so perhaps the experts in this group could help me figure this out.

Thanks for your reply.

[1 Lucky Texan]

RockAuto's shipping prices sometimes make a bargain seem less so.

Maybe see what comes up in an Amazon list for your vehicle. If there's agreement on the part numbers, get the less expensive one?

The issue with both of the above sources, is what to do if there's an issue and you need to return something. RA returns can be trickier than Amazon, but both are trickier than going back down to your local NAPA or Advance Auto for a return or exchange.

OH, just remembered, in the past, Advance Auto has offered a very good cash-back/dsicount on first time customers of their ONLINE sales, that may be worth investigating too.

Ebay may be another route worth checking into. I did have a coworker that had a problem with a rad delivered from an ebay purchase. It was not packaged well and arrived damaged. He had to send some photos back and multiple emails but it worked-out in the end.

I have only bought 1 rad. It was for my WRX and I got it from RA it was a Denso. Smooth transaction. Others here likely have much more experience with this than me.

Edited April 18, 2021 by 1 Lucky Texan

[mrfixiter]

The only agreement I can get on part numbers is if I buy an OEM part. I went to the Advance Auto webpage and the same situation exists as with Rock Auto. I did notice this in the small print in the description of one of the radiators:

Quote

 

Exact Fit for your 1997 Subaru Legacy GT

CSF Aluminum Core Radiator Metal Tank; Automatic, Manual Trans.

 

So I guess the transmission type doesn't matter?

Amazon has one radiator on their list. For $61 and free shipping, that seems like a bargain. I did notice that some of the users' feedback mentioned fitment issues. I really don't want to be modifying anything to get it to fit. Metalwork isn't one of my strengths. Fitment aside, does that seem like a reasonable choice?

As far as NAPA goes, they have a larger selection but they're no competition for Amazon in terms of price.

Thanks for your reply.

 

Edited April 18, 2021 by mrfixiter

[jonathan909]

2 hours ago, mrfixiter said:

RockAuto doesn't seem to offer any tech support

"RockAuto" and "tech support" are two combinations of letters that are not permitted to occur in the same sentence.

They have taken unhelpfulness to previously undiscovered heights.  If you don't see it on the screen in front of you, they don't have an answer either.

How bad can they be?  I was curious what they'd sell a crankshaft (reground by Enginetech) for - it's listed, but as there's no stock there's no price shown.  I asked what the last price they sold them at was, just so I'd have a ballpark number, not a quote.  It took about six increasingly-insistent emails to get past their probably-autoresponders, and when I finally got to a human, the answer was, "I am truly sorry but this is not information that we have available or are at liberty to provide."

[jonathan909]

1 hour ago, mrfixiter said:

So I guess the transmission type doesn't matter?

Since nobody has put up their hand to say it does, I'd guess it doesn't.  Obviously, having some empty tubing in there will reduce the volume of coolant it can hold/cool, but I doubt it's enough to matter.  The only thing I'd be worried about (since I only own Legacy/Outback wagons) is whether the GT version is a different height, but it sounds like you're on it.

[heartless]

no, transmission type does not matter, unless you specifically need the cooling tubes for an auto... you can use the same radiator in a manual just fine, just cap the tube ends to keep dirt out (they should come with caps on them)

It is far more cost effective for the manufacturers to make one radiator that will work in both applications than to make 2 different versions.

[heartless]

23 hours ago, mrfixiter said:

Just to clarify, is that the plastic cap which I'm calling the coolant bleeding screw? If not, where is this plastic cap?

Thanks for your reply.

the "plastic cap" i was referring to is the entire plastic section of the radiator (sometimes top/bottom, sometimes sides, depending on application) - the plastic is factory sealed to the metal part and cannot be serviced.

[mrfixiter]

 

Quote

The only thing I'd be worried about (since I only own Legacy/Outback wagons) is whether the GT version is a different height, but it sounds like you're on it.

I took out a tape measure and measured the dimensions as best as I could with the radiator in the car and the numbers seemed to match the specs +/- a half inch. I suppose I should remove the radiator and measure it again to get a more accurate reading.

56 minutes ago, jonathan909 said:

"RockAuto" and "tech support" are two combinations of letters that are not permitted to occur in the same sentence.

They have taken unhelpfulness to previously undiscovered heights.  If you don't see it on the screen in front of you, they don't have an answer either. 

How bad can they be?  I was curious what they'd sell a crankshaft (reground by Enginetech) for - it's listed, but as there's no stock there's no price shown.  I asked what the last price they sold them at was, just so I'd have a ballpark number, not a quote.  It took about six increasingly-insistent emails to get past their probably-autoresponders, and when I finally got to a human, the answer was, "I am truly sorry but this is not information that we have available or are at liberty to provide." 

Thanks for sharing your customer service experience. I guess they have enough business to service the masses but not enough manpower to answer anything that doesn't apply to their current list of stocked parts. I could not find any e-mail links on their site. Did you fill out a webform or did you get a real e-mail address?

5 minutes ago, heartless said:

It is far more cost effective for the manufacturers to make one radiator that will work in both applications than to make 2 different versions.

Makes perfect sense to me.

3 minutes ago, heartless said:

the "plastic cap" i was referring to is the entire plastic section of the radiator (sometimes top/bottom, sometimes sides, depending on application) - the plastic is factory sealed to the metal part and cannot be serviced

That's the answer I was looking for. Presently, I'm leaning toward the purchase of the Amazon radiator.

Thanks to everyone for all of your replies.

[jonathan909]

4 minutes ago, mrfixiter said:

Thanks for sharing your customer service experience. I guess they have enough business to service the masses but not enough manpower to answer anything that doesn't apply to their current list of stocked parts. I could not find any e-mail links on their site. Did you fill out a webform or did you get a real e-mail address?

RockAuto Customer Service <service@rockauto.com>

But again, I challenge you to pose a question they're capable of answering.

When you look at their prices you'll understand why they're a zero-service company - they exist to move product at volume at the lowest possible price, and that's all.  I'm not dissing them at all - they're my first stop for most parts.  There are exceptions, one being specific components (e.g. the timing parts often discussed here) where you need to be picky about manufacturer for reasons of quality; another being that there are cases (e.g. brake rotors) in which the weight causes shipping cost to negate the savings over local purchase.  Otherwise, fill your boots.