580k master cylinder fluid for brakes

I've got a 580k phase 1 backhoe. Was needing to service the brakes. Wondering what fluid goes in the master cylinder? The master cylinder cap says DOT 3 brake fluid, but then the service chart under the hood says to service them with only TCH fluid. I first thought the cap maybe the wrong lid but it looks factory has 2 wires hooked to it for some reason.

580k master cylinder fluid for brakes