Filling the rear reservoir is tricky and it's tough to see the level. Look at the inside extreme rear of the reservoir. You should be able to see a different level or slight color difference between about the rear half-inch and the rest of the reservoir.

Fill the reservoir to almost the bottom of the fill hole, then slowly move it laterally back and forth and watch the inside rear for the rear reservoir to fill. If you fill the fluid to over the bottom of the fill hole air cannot escape and the rear reservoir will not fill!!!

BTW, it's brakes, not breaks.

Duke