Brakes - Combination Valve

[Jason Spears]

I've just finished replacing my master cylinder for the second time in a week (I hate recon parts) and had a heck of a time bleeding the rear brakes.

Anyway- the button that is under the rubber cover on the combination valve. I've read in other posts that if this is pushed and held in it will allow brake fluid to flow freely through the valve. How hard should it be to push this in? I tried to push it in but couldn't. Is it time for a new valve?

Thanks for the help.

Jason