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Mysterious orange leak

1996 Chevy S-10 2.2L 2WD (87K miles)

I recently noticed the underside of the drivetrain area was getting wet with something. It’s an orange-colored oily fluid that’s not quite red (like trans fluid), and not quite brown (like engine oil), and not antifreeze (I’ve flushed out Dex-cool and use green ethylene glycol). As far as I can tell, it seems to be originating from the A/C compressor. Everything on the driver’s side of the engine is moist to at least a small degree (water pump, power steering pump, and compressor), but I am not losing any coolant or PS fluid. Maybe the compressor is leaking refrigerant oil, from a worn shaft seal or something?

I should mention I’ve had the truck for about a year and a half, and initially the A/C did not work and I was running a shorter belt to bypass the compressor. After about a year of this, I’ve since recharged it and it works great. The orange stuff is quite viscous, almost like differential gear oil. Thoughts?

I googled and all references to orange refer to orange antifreeze, which is contraindicated here.

Except one.

Rust under some conditions can have an appearance that some describe as orangish. The question is how would you get that much rusty water in a drive train???

I have seen that color of rusty water in old steel barrels which got water in them, but that is not a car.

The only thing I can think of is water from the a/c getting where it shouldn’t be, somewhere that has oil or grease in it. But, oil or grease tend to preclude rust, I would think. But, this is a really long shot, I tell ya’. I hope you get some smarter help than me.

Yeah, it’s definitely not antifreeze because I use the green stuff, and I’m not losing any of it (there is also no rust present in it). I’m just not sure if refrigerant oil is colored this way or not.

What type of refrigerant did you use in the A/C? I’ve seen some that use a orange-y looking oil with a leak detecting dye. Maybe that is what you are seeing.

The A/C system leaked and lost its charge. You recharged it. Why should it stop leaking? Have you done pressure checks on the A/C system?

No, I haven’t done pressure checks on the A/C system; what purpose would that serve? I know it leaks, and I know that it will continue to leak. It’s not important enough for me to spend big bucks on to stop it completely. I just wasn’t sure what this stuff was.

I thought it could be refrigerant oil, but having not seen an A/C system leak in this manner (before I’d only seen bubbling refrigerant gas from a cracked compressor casing) I thought I’d see if anyone else has.

Look at the fluid with a black light. It may be a leak detection dye.