Been having problems with my brakes lately. Replaced two napa master cylinders, and still have issues. I've decided to try and work from the top down, I have my old Proportioning Valve out and noticed a rubber cover near the back and an a brass pin that can be pressed.. Is this for bleeding the valve?

I dont want any air to be trapped.
Thanks for any help!
Best Regards
Tom

 

No, that is the reset for when the brake warning light comes on.

 

Oh, great, thank you!

By the way...
The replacement P-Valve is same with exception of the bracket. Moves the whole unit out by inches, and way out of brake line alignment. bummer... Now I'm in the process of cutting the valve from the bracket and welding it to the original bracket.