Gear Cooler Leaking Oil

[1sadler]

My Cummins QSB 5.9 gear cooler is leaking oil from a 45 degree elbow on the oil inlet or outlet. You can see the oil on the elbow in the attached photo. Before I start messing with the elbow and hoses, I thought I should post here and see if it’s ok to just start trying to simply tighten the elbow. My hesitation to just put a wrench to things comes from the red paint marks showing on the inlet and outlet hoses. I’m betting these paint marks are to indicate if the hoses have been loosened and so I’m wondering if that’s telling me something I need to be aware of before I start messing with things. It’s possible I’ll have to loosen one of those hoses if the elbow needs to do a 180. So is there any hazard in just pulling the hose loose and trying to tighten that elbow? And, can I use thread sealer if needed?

Topic

[1sadler]

Thanks! I’ll try your fixes this weekend and report back.

[Rob Schepis]

Plan A:  Remove the line, back up the brass T fitting with a wrench and try to tighten that 45 one more turn.  You may not be able to get it to go around again without over-tightening.

Plan B:  Remove the line. Clean the brass T and the hose fitting 100% and reinstall with epoxy (JB Weld) instead of pipe thread sealant.

Plan B = you’ll never look back..

Here’s a threaded fitting I used epoxy on when installing my gear pressure switch a couple seasons ago.  First attempt of this connection was with a pipe dope, leaked like a severed artery as soon as pressurized.  

[Author]

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