Oil Cooler fittings leaking

[Prime12]

I have oil leaks from between the hard lines and the oil cooler itself. I took the banjo bolts off, used new gaskets and re-torqued the bolts to spec (25ft lbs) but the leak is still there. WTF.

My oil cooler is old but I have brand new OEM lines. Does anyone have any clue what is going on?

[Chris@Rvengeperformance]

those damn things seem to always leak for me. I wonder if switching to a regular copper washer wouldn't be better than the weird oem one.

[rlacasse1]

I used copper on my last VR4 and I never had a leak.

[DrGonzo]

Switch to copper. Fixed the issue I had with mine.

[DocWalt]

Another vote for copper. I couldn't get my fittings to stop weeping with the stock washers, switched to copper and no more issues.

[rlacasse1]

I honestly don't see why they aren't copper from factory when Mitsu uses plain copper every where else, like for the turbo oil feeds. Also across multiple Mitsu cars, like the good old DSM and the 3s.

[Chris@Rvengeperformance]

they are 16mm, right?

[rlacasse1]

they are 16mm, right?

I honestly don't remember, it's been so long since I did that. I took the bolts with me to a Napa and dug through all of their stuff until I found what I needed.

[Prime12]

Ok I found the source of my leak. I had a hairline crack along the threads of the oil cooler housing where banjo bolts screw into. Replaced the cooler, torqued the bolts to factory specs (25ft lbs, which is definitely NOT that tight) and no more leak.

So, if you find yourself having to torque the heck out of your bolts to keep oil from weeping through, you may want to take a closer look at your oil cooler.