Oil Cooler Fitting Seals

After pressure testing the cooler and hoses it appears I have a oil leak at the seal between the 16mm to AN-8 steel adapter and the 1st gen early model cooler threaded bungs. When the system was first put together Stat-O-Seals were used but they began to leak after about 5 weekends even after subsequent tightening. It appears the flange on the fitting has an OD that is not much bigger than the rubber insert of the Stat-O-Seal.

Yesterday, after putting everything back together and using aluminum crush washers it leaks even worse. OEM crush washers are NLA. I have not tried Dowty seals and am concerned because the AN sized units have an ID that is a bit larger than 16mm. There are metric sized pieces but Google showed only a place in the UK and Australia.

Any ideas?

Take it to a local hydraulic fitting store. They can fix you up with something.

Tom- As mentioned above, aluminum or copper washers are available at a hydraulics shop, A-Performance in Decatur or even a few hardware stores (I get mine at Ace Hardware in Tucker). However, you should also check the bungs on your cooler. The last two times I've had leakage at the fittings, the problem turned out to be that the bungs themselves were split. It may be just a hairline crack (you have to look very closely), but it will dribble oil out.

The 1st gen coolers are notorious for having splits in the bungs. Throw it out and install a 2nd gen cooler.

The bungs are indeed split and I plan to clean the cooler up tomorrow, lighty screw some Al fittings into the bungs, take it to a shop on Monday and have them weld the whole thing up.

:fingerscrossed:

We've tried that. You still end up with the flat seat area having a crack in it. If you absolutely have to salvage the cooler you're best to just weld the fitting to the cooler.

Did you weld aluminum fittings onto the cooler thereby eliminated the flat area and seal altogether?

At this point the cooler is junk and it should work fine after that.

Just replace it. Check out Pegasus.

http://www.pegasusautoracing.com/pro...p?Product=1210

or like someone else said 2nd gen cooler, check out car-part.com. Around Pgh, PA there were several 2nd gen coolers ranging from $50 to $150.

Quote:

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Originally Posted by tom_sprecher

Did you weld aluminum fittings onto the cooler thereby eliminated the flat area and seal altogether?

At this point the cooler is junk and it should work fine after that.

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After doing what you described you described in the first post without even thinking there would still be a crack running the length of the threads on the inside and having the cooler leak again we tossed it in the trash and threw a 2nd gen cooler on the car. We had 3 or 4 sitting on a shelf so it was a no brainer. Even if you have to buy one they can usually be had for $50 or less. The inlet and outlets aren't as convenient in the 1st gen chassis but it's not a deal breaker.

If I had a sentimental attachment to the cooler I'd start by welding the fittings to the bung as well as repairing the crack. Will be the only way to stop the leak for good.

Welding did not work as the end tank was too corroded and difficult to clean where the bung and end tank get real close. I tried to get another one today but it turns out what I have been using is actually a RX-3 oil cooler and the 1st gen unit is about 2 inches longer. With the way I mount it there is no way it will fit and I really don't want to re-fab the mounts and duct work if the 1st gen unit is prone to cracking.

I'll see what I can get aftermarket wise, but I think this kills my chances of racing this weekend at Road Atlanta. There's not enough time to get everything and make it.