It would appear that you have a Grinnel Union upstream of your filter . They are notorious for loosening over time (or) leaking premature due to vibration . When did you check your unit last , often a minute leak will look worse on cement with Hyd . Oil lol . If the Grinnel is the culprit , selection of a Steel Hydraulic Union rather than a cast iron unit will solve any chronic leakage via this fitting . P.S. Ensure you use telfon rather than permatex on your Hyd Joints ...aka Ewalk .

Thanks for the good Points related to the plumbing. I was tempted to just start tightening all
the joints. “Age settled me down to
cleaning all the joints to observe after the next major use (vs. 5 years). There is no end to learning New Technology or
Mechanics “new to you”. I was pleased
not to see major leaks during my cleaning and testing. I know there are small leaks and some slowing
and observing to be done.

Should I feel any signs of heat related to hydraulic at Cylinder,
Tank or Lines? My only sign of heat is
at my 1HP Farm Motor in the TX heat. My
average small jobs in heat are approx an hour. I have my logs close, on ends ready
to be “flipped on an 8” step vs lifted onto the splitter” (from my seated
position) LOL!

My usual goal is to split under 70 degree weather, or one hr
or until my motor is too hot to my bare hand.

Alternative explanation: hygroscopic chemical from plastic bottle in corner. It is more likely if that bottle is cracked, but a little powder on the outside could have done it as well.

hy·gro·scop·ic

ˌhīɡrəˈskäpik/

adjective

adjective: hygroscopic

(of a substance) tending to absorb moisture from the air.

Based on the shape of the oil stain, I would suspect the leak is more toward the center of the splitter. Possibly at the hydraulic cylinder itself. It is difficult to estimate from the pictures.

However if you look at the shape of the stain at the small end (Forward to the right) is some distance to the right of the post, and at least the distance from the post to the wall toward the center of the building. To me it looks like this spot on the front right is where the oil fell and then ran toward the corner of the building.

Assuming the splitter has been in the same position for some time and it is used in place

Bingo And Thanks!! to the
good suggestions I received, I had to verify and define some of the info. Such As:

1. I had to define Grinnel Union where I found a fresh leak (if I defined it correct).

2. The leak was Dead Center
of the original spot and clean (related to filter vs cylinder.

3. My almost empty Fire Ant Orthane’s
bottle’s smell was to keep the past animals away.

One quick feel, the leak was
at the Elbow before the union toward the filter. The union reduced the work and I used Teflon Tape
vs Pipe Seal with Teflon this trip. The
work was tilting the splitter so the 5 Gal Tank would hold the 2.5 Gals of fluid
tilted. It did on it’s side. I pressure tested the joints again with no
instant leaks. I am done for now. I’ll
check back in a few days or wait for the next splitting job.

I need to take a break and
finish trimming a bathroom’s floor as my planned job after my 2 mi walk. I just had to investigate the leak and info. That made my day. If all goes well the trimming might take an
hr.

Please comment on if I should
feel any heat related to the hydraulics which I have not noticed. I know what I read about letting systems cool
could have ref to different models.

Loger , Good to hear you found the leak origin , hydraulic oil will travel (capilliary action) and makes detection dicy at best since the elbow joint is relatively close proxcimatity to the Union. As for the heat transfer from the hydraulic oil , this is relatively normal when you consider the pressures and piping friction involved . I would just check the return reservoir for excessive foam , which could indicate a control (relief) or directional valve leaking through which would produce additional system heat . As for your electric motor , do not run the unit when external surface temps exceed 143 F. Rule of thumb human skin contact for more than 5 seconds will cause burn. Normally in your Texas Heat early morning or late evening would be more advantageous lol . All the Best aka Ewalk ! P.S.S. Speaking of heat , even in the Great White North the Temps hit 85 F yesterday , which made cutting and bucking & stacking of two White Birch and one 1 Canadian Maple more work then this old timer anticipated lol . paying for it today !