Let us know what you find out.
It’s possible your mc piston seal is worn given the age
OK, so small update:
I took the neutral bulb out and it was corroded as heck. I flushed the socket out with some WD-40, and scraped the contacts with a screwdriver the best i could, re-flushed again and put a new bulb in, boom, worked.
Checked the other 2 bulbs to be safe, they were clean.
IDK what happened with the neutral that that happened other than some water got in it
As for the MS, I did that trick again with putting the MS above the hose (parked on a hill, right side in high) and pumped the brake for about 10 minutes straight (HAND CRAMP!!!!!), re-tried the brake (all assembled) while going 15mph or so, no improvement, still need to pump it 3+ times to even get it to engage.
I think the MS is just worn out, probably never replaced by the PO.
When i bought it, the front brakes were shot and half-locked, so I did this SuperATV kit instead of re-building, never tested them original. The PO did not take very well care of this thing (why I gave her the name "Scar", she shows her battle scars but keeps on trucking)
I will report back when my non-OEM one comes in, and i install it (and test).