So ive gone ahead and bled everything. No air in the lines. I have one of those cheap brass combination valves for front disc and rear drums. There seems to be a leak from the brake light warning sensor. Brakes are okay when pumped when car is off but it completely depresses when the car is on. Could the proportioning valve be the culprit or should i be looking elsewhere. I know these cheap chinese proportioning valves are notorious for failing. Any recommendations?

 

Did you just do an upgrade to the brake system? If so, explain what you have done so far.