Motorcycle Repair: Bleeding brakes Seca 750, hydraulic brake fluid, yamaha seca 750

Question
Hi Mark:
I also bought a 1981 Yamaha Seca 750. It had been sitting for four years or so, and the front brakes were seized. I bought a set of good used calipers on eBay, and installed them. Of course the brake lines were empty, and to bleed the brakes I filled the reservoir and pumped the brake lever. I did it as you have in your website, and Haynes manual. No fluid came out of the bleeders, and when I took the hard line off the master cylinder, also no fluid came out.
Do you have any ideas why? According to your page it should be easy, but nothing worked for me.
Do I have to purge the master cylinder to get the fluid flowing? And if so, how do I do that?
Regards:
Anton

Answer
Hi Anton,

Bleeding hydraulic systems can be frustrating.

Priming the master cylinder may be necessary. First, try reverse bleeding the system to fill the lines with hydraulic (brake)fluid. This may prime the master cylinder.

Reverse bleed by pumping fluid through the bleeder valve on the calipers.

Reply with your email address and I'll return tech files on the topic.

Respectfully,
Mark Shively