928drvr86.5

CR Aluminum radiator leaking at the DS end tank to core junction. What to do, I purchased this radiator because I thought the plastic end tanks and gaskets on the Behr/OEM radiator were BS, turns out the CR radiator is worse.

Jeff Spahn was at my house a week ago showing me his new SC setup and relating the story of how he had to replace his CR radiator because it was leaking at the end tanks, I told him mine was approaching 6 years old with no problems - I cursed it. Jeff left, I went out to pull the car in 1/2 hour later and found a small puddle of coolant on the DS right below the radiator hose so I thought it was the hose and ordered a new one. Further investigation found what's shown in the picture.

928drvr86.5

For reference, the picture was taken at the driver side top right next to the oil cooler connection.

jeff spahn

You can try to have F&S radiator epoxy it but really it most likely wont' work. Roger has some Behr radiators I think. Good luck!

SeanR

Great to meet you last week Ben, and as far as what to do with it? Paper weight. Buy a new Behr and sleep well for 15 or so years.

j.kenzie@sbcglobal.net

928 Int'l sells used Behr units for around $500, pressure test with one year guarantee. 1/2 price sale coming up soon maybe. I had mine repaired for $165.
Good luck,
Dave

928drvr86.5

I may try to epoxy it myself over the winter months. What am I out, besides my time? It sits over winter anyway.

928drvr86.5

Just a matter of getting things cleaned/etched properly and finding the proper epoxy. If you look at the weld running the length of the end tank, adjacent to the core, it provides a good 3/16" or so levee for the epoxy to pool around the core. We'll see what happens.

jeff spahn

That's just what Mike @ F&S said to me. I was only out $150 or whatever for him to try so it wasn't big money.

ajricker

So my question is. all of the aluminum radiators that have failed. Did they have aftermarket electric fans installed?
The reason I ask is it looks like the cooling tubes on the top of the radiator are pulled back towards the engine.
I'm wondering if the added weight of the fan assembly hanging from the radiator, and the vibration could be causing it to fail?
Just curious. I have both a 928 motorsport radiator and belt driven fan replacement assembly.

928drvr86.5

Yes, i have a dual electric fan hanging off the back of mine.

Tails

With s leaking end tank on the inlet side, it can be fixed if you can obtain a new "O" ring.
As the side indicated is the hot inlet side of the radiator the "O" ring over time flattens out, sets and finally leaks.
Do not try to bent the radiator tabs in to tighter position to stop the leaks, as there can be two unwanted results:
1. it wont fix the leak; and
2. when you try to pry open the tabs it will cause the tab to fracture.

I recently had a leaking aluminium radiator on the inlet side. Removed and when pressure tested to 12 psi "cold" it was leaking from both sides of the end tank.

Check the tabs to see if they have been opened out or re bent in tighter, because if they have then there is a greater possibility for the tabs breaking off.

The tabs were prised up so a just to clear the flange on the end tank, the end tank removed, cleaned out the debris flushed through the tubes and some tube need to be air blown to clear debris out, fiitted a new "O' ring replace the end cap and reseated the radiator tab pieces using vice grips to the original position.

Only reposition the tabs that were prised open as there are some that are not bent over.

To ensure a good seal the tab section of the radiator core will need to be fitted parallel to the flange on the end tank, this make take some careful hammering to get it parallel.

When reinstalled in car the total system was pressured tested to 12.5 psi cold and it held this pressure for 5 hours.

Car now back on operation and all appears in order with on leaks.

The radiator is the original aluminium radiator and is now nearly 24 year old.

928drvr86.5

I forgot I started this thread back in October, I have not been spending much time here lately. I have not replaced the radiator as of yet, but want to get it done soon. I will buy new as I don't want the PITA of attempting a repair only to have it fail and then mess with the transmission cooler lines re - filling etc. $1500 seems nuts for the Behr unit, I see 928 Motorsports has an all aluminum, but looks like the same CR racing, no?

jcorenman

I think the problem with any of the welded-aluminum aftermarket radiators is this (from the 2012 thread):

I don't think any of the aftermarket companies make their own cores, and that is where the problem lies. Some folks have reported success with epoxy or JB Weld, but I am thinking that is only a temporary fix.

The Behr cores are quite good, the Behr radiators fail when the plastic end-tanks start leaking, usually at the upper-right (passenger-side) "hot" inlet. But they are also repairable-- by you, or by a good radiator shop, or buy a rebuilt Behr from 928 Int'l ($600-800 depending on year). Behr's are common so lots of radiator shops know how to replace end tanks, and there are some good write-ups here.

Another possible issue is the rubber radiator mounts top and bottom. Rubber gets hard as it ages, which means the radiator is no longer "floating" and isolated from vibration. I believe that the mounts are cheap and available, so it makes sense to replace them along with the radiator.

z driver 88t

Considering the OEM Behr radiator for my 1987 Mercedes 560SEL is less than $350, I have always theorized that we 928 guys were getting screwed on the OEM radiator costs - not by the vendors, but by the supplier. I've read all of Greg's posts on the subject and highly respect his expertise. I just can't imagine that Behr cooling core for my 1984 4.7L Porsche V8 is 4 times more complex and better build quality than the Behr cooling core in my 1987 5.6L Mercedes V8 from the same era. Who knows, I'm probably wrong - but to me it's highly suspect.

However, I too had an end tank failure at two years from a 928MS aluminum radiator. Carl was great and stood behind his product and sent me a new one for a nominal fee and I have no complaints. Since then, 928 Motorsports has increased their warranty to two years on their aluminum radiators - although I understand that with a 5 year failure it would not help in your case.

As I recall, the 928MS radiators are assembeld by Howe which has a pretty good build reputation and has been around for 30 years. If the second one fails I'll probbaly bite the bullet and go back to OEM, but I will do it grudgingly.

Carl Fausett

Our radiators have welded cooler fittings, not the PAL-nut secured fitting shown in post 1. We noted they were a failure point years ago and designed the PAL-nuts out of our radiators to eliminate the problem.