Aluminum radiator leaking at different spots, a common thing?

[lookforjoe]

That's exactly what I'm debating. As mentioned I made custom mounts for mine. I had to, one of the mounting studs on the alum rad broke off. Therefore I could locate the new mounts anywhere I feel is best. Currently they are under the lower frame similar to the stock location. But now I'm wondering if it would be better to move them under the tanks. That isn't as ideal a location in terms of fabrication though. The support member that the rad sits on narrows at the ends before reaching the tanks, so it is a more difficult spot to attach my custom mounts to. And the rad has less open room for mounts to clear at the tanks; the drain plug on one tank and the lower hose neck on the other tank are pretty much in the way. I'll see if I can get a couple pics later today to illustrate this better.

Mine is setup this way:

So, the rad isn't actually bolted to anything - whcih turned out to be a very good thing in my case

The rubber block is either a swaybar endlink bushing, or a modified exhaust hanger, can't recall which I used now. It is located by the bolt head that
retains the stay in the rad support. I put a section of velcro on the rad where it sits on the stay. No evidence of chafing/wear though.

 

[Dr.Jeff]

Mine is setup this way

That is very similar to what I made. The bracket on mine comes up on both sides of the rad (red line), and the rubber wraps around the rad (blue line):

I just welded the brackets to the rad support rather than bolt it on. The arrangement is meant to act like the stock mounts on other cars. Here is the rubber insert for a Alfa for comparison:

I should order a couple of them, instead I just have a rectangle piece of synthetic rubber sheet stuffed in there. Once mounted they seem very secure though.

 

[MikeHynes]

That is very similar to what I made. The bracket on mine comes up on both sides of the rad (red line), and the rubber wraps around the rad (blue line):
View attachment 32234

I just welded the brackets to the rad support rather than bolt it on. The arrangement is meant to act like the stock mounts on other cars. Here is the rubber insert for a Alfa for comparison:
View attachment 32235
I should order a couple of them, instead I just have a rectangle piece of synthetic rubber sheet stuffed in there. Once mounted they seem very secure though.

The 124 uses this type of setup. You should be able to find parts them them fairly easily.

 

[Dr.Jeff]

Mine sits on rubber blocks set under the end tanks

Got some pics of the rad I have to help see what I'm thinking.

Here is what I was referring to as a expansion joint. However it might not be. There is a gap on either side but the center portion (across the flat bottom) is welded solid. So now I'm not sure if it allows movement or not:

Here's the broken mounting stud. Yet another issue with these units:

This is why I'm not certain if a saddle style mount can be put under the tanks. On one tank the hose neck doesn't leave much room:

And the drain plug on the other tank leaves even less room. Blue arrow is another look at the frame joint:

This all relates to the type of mounts that I made:

Here is where it would be positioned if I moved it under the tank:

Anyone know what that tab (blue arrow) is for?

And the support member that the rad sits on gets narrower at the ends under the tanks. That allows less realestate to add the saddle to (it would take some extra fabricating):

So I'm not sure if it is worth moving the mounts out to the tanks or not. But I can see why your new mounts are more open on one side, to avoid the neck and drain.

 

[Dr.Jeff]

The 124 uses this type of setup. You should be able to find parts them them fairly easily.

Thanks Mike. I actually looked at them. For me it was just easier to make my own. Plus that way I know they fit the size of this particular aftermarket rad.

On the 124, if I recall correctly I believe the tanks are across the top and bottom? So as far as how the mounts interact with the core's frame vs the tanks, it is very different from the X (with the tanks on the ends).

 

[paul]

The brackets with rubber look good, but will they fix the problem?

The top left and right corner have movement and stress the seam.
I assume this movement comes from the top and bottom mounting point moving in the car.
This movement is not stopped or absorbed when the bottom brackets are holding the core or the tanks on the side.

 

[lookforjoe]

The brackets with rubber look good, but will they fix the problem?

The top left and right corner have movement and stress the seam.
I assume this movement comes from the top and bottom mounting point moving in the car.
This movement is not stopped or absorbed when the bottom brackets are holding the core or the tanks on the side.

I don't have a stock setup anymore - my recollection is the top is secured by a center pin in a rubber grommet, then the bottom by the two rubber grommets. That setup would not create a load on the upper corners, since they are 'free', not anchored in any way. Any body twist should not apply stress there as far as I can see. Am I missing something?

 

[ecohen2]

I had the dreaded alloy radiator leak and it was 100% due to weak welds on the radiator. After a couple of years it started developing hairline cracks along the seams and a drip would occur at the bottom after the radiator got to temperature. For the longest time I thought the leak was at the bottom corner, but we couldn't figure out where it was coming from. Eventually I put painters tape along the seams and could see where the tape was getting wet. The vendor I purchased the radiator from said that was normal and I should take it to a shop to have repaired. I decided to wait a couple of months for Matt Browns new radiator and have not had an issue since installing it...

 

[paul]

I don't have a stock setup anymore - my recollection is the top is secured by a center pin in a rubber grommet, then the bottom by the two rubber grommets. That setup would not create a load on the upper corners, since they are 'free', not anchored in any way. Any body twist should not apply stress there as far as I can see. Am I missing something?

The way I imagined it, was holding a piece of paper landscape to simulate the way the radiator is held in place.
When I move the top or bottom, to simulate the car going over bumps, it are the not anchored corners that move the most.
Of course I don't know how much this comparison is valid.

 

[paul]

I had the dreaded alloy radiator leak and it was 100% due to weak welds on the radiator.

I got mine repaired and hope the repair will hold.
Although I guess my chances are slim, as it will probably start leaking at other spots.
The good thing is, even when leaking the car doesn't overheat.

 

[Dr.Jeff]

but will they fix the problem?

Paul, I have no idea but honestly I doubt it. Frankly the mounts I made were not intended to fix anything other than the broken mounting stud on the bottom of the aluminum unit (pic below). At the time when I made the new mounts I hadn't even considered the whole concept of the rad twisting or flexing. So your questions are good ones that got me thinking about it after making those mounts. I've been trying to determine if the placement of the mounts (lower and upper) really make much difference. @lookforjoe makes a good point, the single upper mounting pin may allow enough movement to alleviate any stress on the unit. And my lower mounts will likely not be much different from the stock ones. So I doubt I've improved anything other than repair the broken stud. I tend to agree with @ecohen2, the biggest issue is the quality of the welds/construction.

My next concern is the aluminum studs on the back of the rad that mount the cooling fans. They are also weak and some already have damage (stripped threads). I haven't addressed that aspect yet. I am replacing the sock fan with a pair of aftermarket ones. They are much lighter in weight than the monstrous stock one, so hopefully that may extend the life of those pathetic mounting studs. These aluminum rads are not worth the money in my opinion. Hopefully the new and improved version is much better.

 

[Dr.Jeff]

I got mine repaired and hope the repair will hold.

Same here.

 

[Dan Sarandrea (Phila)]

Wondering if use of the lightweight aftermarket fans vs. the hefty OEM fans could be somewhat of a factor. The fans are mounted directly to the rad in either case, so stands to reason the heftier OEM fans would stress the overall structure of the rad more than the lighter aftermarket ones.

 

[paul]

Wondering if use of the lightweight aftermarket fans vs. the hefty OEM fans could be somewhat of a factor.

Something I noted, and is also visible in the photos, the right side has more repairs as the left side.
Could be a coincidence, but I mounted the fan on the right side.
Especially the frame, the fan is mounted on, makes the right side more rigid.

 

[paul]

A quick update.
After installing the repaired radiator everything looked okidoki.
No more small drips on the floor.

Unfortunately after something like 100 miles it has started leaking again.
Not much, but coolant can be seen between the ribs.
This at the same spot as before.
It seems repairing it, ones it has started leaking because of cracks, is no solution.

 

[JimD]

Bummer paul. I went ahead and installed my 2nd BobG radiator in my very stock 86X. I don't think it improved the cooling too much, nothing like what I see in my 85X. Makes me wonder if the 85X has a thermostat in it, or maybe just a decent weep hole drilled in the thermostat itself.

Anyway, it is way too early to know what will happen with this 2nd radiator. I will try to remember to come back here if it ever develops a leak. I did put 2 fans on it, one stock and one modern, so both sides have a fan frame as reinforcement between the top and bottom radiator rails.

 

[Dr.Jeff]

Unfortunately after something like 100 miles it has started leaking again.
Not much, but coolant can be seen between the ribs.
This at the same spot as before.

I don't recall for sure, but if Paul's leaks are from the same location as others have experienced with certain aluminum aftermarket radiators, then I'm not completely surprised that repairs may not be 100% successful. I'm referring to the end plates at either end of the core, inside the side tanks. Where the actual cooling tubes connect to the end plates. That seems to be a common source of leaks, more than the tank seams, etc. And leaks in that location cannot even be accessed without completely removing the side tanks. Furthermore they may not be fully able to re-solder them even with the tanks off. In my opinion it is more a quality issue with the components used to fabricate the units. Those end plates are a part of the core itself.

 

[paul]

I also strongly believe it is a quality issue.
It seems not possible to resolder the tubes in a way to solve the problem completely.

 

[RJ80]

When I switched to a VAS aluminum radiator, I kept my stock radiator to re-core some day. Seems like that was the right call.

 

[Dr.Jeff]

I kept my stock radiator to re-core some day. Seems like that was the right call.

I think for most applications that is true. Certain exceptions might require more cooling capacity, such as a very modified engine, living in an extreme (hot) climate, and/or having A/C in stop and go traffic. For those needs I still like the VW radiator mod as a good option.