Mysterious brake Fluid/ clutch fluid leak

I have a leak that I can’t find the source of. I know it’s not motor oil since it doesn’t leave the driveway stained, and it’s not ATF from the power steering because the fluid isn’t amber. So I narrowed it down to Dot3 which is used on the brakes and clutch. The only place I can see it dripping from is the oil filter, but again it’s not dark or staining the driveway. It does dry up after a few hours in the sun as well. Has anyone else had this issue? It’s driving me nuts not being able to find the source.

 

That drip on the bottom of the oil filter looks green

brake master cylinder plungers failing dripping into the brake booster?

The master cylinder end at the brake booster there’s a weep hole on the bottom.
Check there.

 

I doubt that is brake fluid.

 

Looks green right?

 

Drys up, no stain on the driveway? Windshield washer fluid?

 

What color is the antifreeze? If it's NOT pink and is green, the issue may lie there. I would be starting with checking hoses and clamps, I see some have been worked on or replaced already.

 

That's a strong clue that it's not petroleum based. While those things will dry, they'll stain too.

My official bid is coolant. And that someone has installed the incorrect coolant somewhere in it's life.

 

Yeah, gotta be coolant.

 

right above oil filter there is an oil cooler
the oil cooler has inlet and outlet that cools the oil by coolant flow

here:

 

OP have you checked the level of any of the above fluid? My first step after seeing a leak is checking the fluid levels of all possible sources of that leak

 

either tighten both worm clamps on coolant hoses(one pictured looks AM/lil loose IMO)
then monitor the leak
or
fix correctly
-drain oil/remove oil filter
-remove oil cooler.....pretty big bolt that holds on the OC.....my Subaru is 24mm
-remove both coolant hoses and trim better and reattach
-install new oil cooler gasket
-re-install everything
-change oil filter/fill with oil