Can't get lever pressure while bleeding front brakes

[albertaphotog]

I bought this after market master cylinder, http://cgi.ebay.ca/FRONT-BRAKE-MASTE...t_26515wt_1026
I can't get any pressure built up on the lever at all. I'm using a mighty vac and no matter how much fluid I draw, still no pressure. I've never bled brakes before but think I am doing it right. The bike is a 79 gs1000L. Anybody have any ideas for me. I'm starting to think the master cylinder is defective.

[tkent02]

Did you bench bleed the MC?

[albertaphotog]

Errr, no. I don't know how that's done. I didn't have any problem with the back brakes. Is there a procedure I can follow to bench bleed the master cylinder. I appreciate the help.

[tkent02]

Try this: Leave the Master cylinder on the bike, take the brake line off the master cylinder, squeeze the lever with your finger over the port where the brake line goes. Let the air out, don't let any back in. Soon it should start to pump fluid out under pressure when you squeeze the lever, it will force fluid past your finger very easily.
Then hook the hose back up and go from there.

[albertaphotog]

I will give it a try tomorrow and post how it worked. Should I have had to do this for the rear, I didn't and seem to have really good pedal pressure. Thanks again.

[tkent02]

Sometimes it's easy, sometimes it's not.