69 Chevelle Re-Fresh...

[Too Many Projects]

Sounds like the valve in the prop has shifted and is blocking the rear port. It needs to be centered again by removing the electric sensor. Sometimes a person can use a small jewelers screw driver thru the sensor hole to pry the valve piston back in place. Other times, you need to remove the cap on the end to move it. There is a tool to insert to prevent it from moving when bleeding one end before the other. RPOLS3 has gone thru this recently and bought the tool. The way I avoid this, is by gravity bleeding all 4 corners before pedal/pressure bleeding.