82 KZ440A2 front master cylinder

G'day Fellas.
Checking the brakes I found the caliper was not releasing the disc fully, getting hot on a short ride and hard to push into the shed. With the caliper removed but still piped it the piston would not push back. Removed the hoe and it would push back. My attention turned to the master. A bit of crud in there but I've seen a LOT worse.
My question is. There appears to be two holes in the base of the reservoir. One is open to the cylinder but the other appears to be blocked. Looking down the cylinder I can't see any indication that this hole is supposed to be open. Is it and what size if it is.
Thanks in advance.
Cheers.
Musky

Both holes should to be open to the reservoir and MC sleeve. Use a thin fishing Nylon line to open and clean holes.

G'day Scirocco, thanks mate.
Just as I suspected. I tried a tip cleaner and even a thin pointed scribe to no avail. Looking down the cylinder I couldn't see evidence of that hole. It must be blocked good and proper. I'll try a 0.5mm drill hoping it doesn't throw a burr into the cylinder. Picking up a kit today.
Cheers

Success. That hole was seriously blocked. I used a 1mm drill by hand till I felt it take metal then used a 0.5mm tip cleaner to push through. increased tip cleaners till found hole size. For the record it's 0.9mm. All back together and working fine.
Thanks again Scirocco.
Cheers