I used my thumb while my wife pumped the brake pedal. Took a couple times until you get enough fluid on the other side of the prop valve then it stays centered.
It's a safety feature in case you lose all pressure to the rear line. When too much fluid rushes past the valve it pulls it over and closes that path, so you don't lose all your fluid on the ground and still maintain pressure to the side that works. While the brake pedal is being pressed, just push the needle in with your thumb nail. Each time will let a little past until the line is full enough that the pressure doesn't trip the safety valve.
Press the pedal down and hold
Open the bleeder on the passenger side wheel cylinder (nothing will come out)
Go up front and press the needle in
Back to the wheel cylinder and close the bleeder
Release brake pedal
Rinse and repeat until the needle stops tripping. The brake light will go off on the dash.
Then bleed the rest of the air out as normal.
It's a safety feature in case you lose all pressure to the rear line. When too much fluid rushes past the valve it pulls it over and closes that path, so you don't lose all your fluid on the ground and still maintain pressure to the side that works. While the brake pedal is being pressed, just push the needle in with your thumb nail. Each time will let a little past until the line is full enough that the pressure doesn't trip the safety valve.
Press the pedal down and hold
Open the bleeder on the passenger side wheel cylinder (nothing will come out)
Go up front and press the needle in
Back to the wheel cylinder and close the bleeder
Release brake pedal
Rinse and repeat until the needle stops tripping. The brake light will go off on the dash.
Then bleed the rest of the air out as normal.